|   | (Date of report)                  | May 20, 2011 |
|--------|-----------------------------------|--------------|
|   | (Date of earliest event reported) | May 18, 2011 |

| Delaware                     |   | 1-12202      |   | 93-1120873          |
|------------------------------|--------|--------------|--------|---------------------|
| (State or other jurisdiction |   | (Commission  |   | (IRS Employer       |
| of incorporation)            |   | File Number) |   | Identification No.) |

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| Item 7.01 |   | Regulation FD Disclosure                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|      |   |  On May 18, 2011, we announced we will participate in the National Association of Publicly Traded Partnerships Investor Conference in Greenwich, Connecticut, on Thursday, May 26, 2011.  A copy of the news release is attached as Exhibit 99.1 and is incorporated herein by reference.   Terry Spencer, chief operating officer of ONEOK Partners, GP, L.L.C., our general partner, will present at the conference at 8 a.m. Eastern Daylight Time (7 a.m. Central Daylight Time). The conference will be webcast and will be accessible on our website, www.oneokpartners.com.  A replay of the webcast will be archived for 30 days.  We will also post the presentation on our website that morning, beginning at 8 a.m. Eastern Daylight Time (7 a.m. Central Daylight Time). The information disclosed in this Item 7.01, including Exhibit 99.1 hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the Exchange Act), or otherwise subject to the liabilities under that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act except as expressly set forth by specific reference in such filing.  |
| Item 9.01 |   | Financial Statements and Exhibits                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|      |   |  Exhibit                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|      |   | 99.1   News release issued by ONEOK Partners, L.P. dated May 18, 2011.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|      |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |

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|   |         |   | ONEOK Partners, L.P.By:  ONEOK Partners GP, L.L.C., General Partner         |
|--------|--------------|--------|---------------------------------------------------------------------------------------|
|   |         |   |                                                                                  |
| Date:  | May 20, 2011 | By:    | /s/ Robert F. Martinovich                                                             |
|   |         |   | Robert F. MartinovichSenior Vice President,Chief Financial Officer andTreasurer  |