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**EXHIBIT 31.1**

**CERTIFICATION**

| 1. | I                have reviewed this quarterly report on Form 10-QSB of Rexahn                Pharmaceuticals, Inc.; |
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| 2. | Based                on my knowledge, this quarterly 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 quarterly report; |
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| 3. | Based                on my knowledge, the financial statements, and other financial information                included in this quarterly report, fairly present in all material                respects                the financial condition, results of operations and cash flows of                the small                business issuer as of, and for, the periods presented in this quarterly                report; |
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| 4. | The                small business 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                small business issuer and have: |
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| 5. | The                small business issuer's other certifying officer and I have disclosed,                based on my most recent evaluation, to the small business issuer's                auditors and the audit committee of the small business issuer's board                of                directors (or persons performing the equivalent                functions): |
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| Dated:  August 14,                2007 |   |
|-------------------------------------------------------|--------|
|                                                  |   |
|                                                  |   |
| /s/                Chang H. Ahn                       |   |
| Chang                H. Ahn                           |   |
| Chief                Executive Officer                |   |

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