**Exhibit      99.4**

**CERTIFICATION      PURSUANT TO RULE 13a-14 OR 15d-14 OF THE SECURITIES EXCHANGE ACT OF 1934, AS      ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF      2002**

| 1. | I                have reviewed this annual report on Form 40-F of YM BioSciences                Inc.; |
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| 2. | Based                on my knowledge, this report does not contain any untrue statement                of a                material fact or omit to state a material fact necessary to make                the                statements made, in light of the circumstances under which such statements                were made, not misleading with respect to the period covered by this                report; |
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| 3. | Based                on my knowledge, the financial statements, and other financial information                included in this report, fairly present in all material respects                the                financial condition, results of operations and cash flows of the                issuer as                of, and for, the periods presented in this                report; |
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| 4. | The                issuer’s other certifying officer and I are responsible for establishing                and maintaining disclosure controls and procedures (as defined in                Exchange                Act Rules 13a-15(e) and 15d-15(e)) for the issuer and                have: |
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|   | (a) | Designed                such disclosure controls and procedures, or caused such disclosure                controls and procedures to be designed under our supervision, to                ensure                that material information relating to the issuer, including its                consolidated subsidiaries, is made known to us by others within those                entities, particularly during the period in which this report is                being                prepared; |
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|   | (b) | Evaluated                the effectiveness of the issuer’s disclosure controls and procedures and                presented in this report our conclusions about the effectiveness                of the                disclosure controls and procedures, as of the end of the period covered                by                this report based on such evaluation;                and |
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|   | (c) | Disclosed                in this report any change in the issuer’s internal control over financial                reporting that occurred during the period covered by the annual report                that has materially affected, or is reasonably likely to materially                affect, the issuer’s internal control over financial reporting;                and |
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| 5. | The                issuer’s other certifying officer and I have disclosed, based on our most                recent evaluation of internal control over financial reporting, to                the                issuer’s auditors and the audit committee of the issuer’s board of                directors (or persons performing the equivalent                function): |
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|   | (a) | All                significant deficiencies and material weaknesses in the design or                operation of internal control over financial reporting which are                reasonably likely to adversely affect the issuer’s ability to record,                process, summarize and report financial information;                and |
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|   | (b) | Any                fraud, whether or not material, that involves management or other                employees who have a significant role in the issuer’s internal control                over financial reporting. |
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| Dated: September              28, 2005 |                                                                            |                              |
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|                                             |                                                                            | /s/              David G.P. Allan |
|                                        | David              G.P. Allan                                                   |
|                                        | Chief              Executive Officer (Principal Executive              Officer) |

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