**Exhibit 31.1**

**CERTIFICATION PURSUANT TO RULES 13a-14 AND 15d-14 UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED**

I,John Kaiser, Chief Executive Officer and Director of the Registrant, CrdentiaCorp., certify that:

1.             Ihave reviewed this quarterly report on Form 10-Q of Crdentia Corp.;

2.             Basedon my knowledge, this quarterly report does not contain any untrue statement ofa material fact or omit to state a material fact necessary to make thestatements made, in light of the circumstances under which such statements weremade, not misleading with respect to the period covered by this quarterlyreport;

3.             Basedon my knowledge, the financial statements, and other financial informationincluded in this quarterly report, fairly present in all material respects thefinancial condition, results of operations and cash flows of the registrant asof, and for, the periods presented in this quarterly report;

4.             Theregistrant’s other certifying officer and I are responsible for establishingand maintaining disclosure controls and procedures (as defined in Exchange ActRules 13a-15(e) and 15d-15(e)) for the registrant and we have:

(a)                                  designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this quarterly report is being prepared;

(b)                                 evaluatedthe effectiveness of the registrant’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures as of the end of the period covered by thisquarterly report based on such evaluation; and

(c)                                  disclosedin this report any change in the registrant’s internal controls over financialreporting that occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that hasmaterially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and

5.             Theregistrant’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to theregistrant’s auditors and the audit committee of the registrant’s board ofdirectors (or persons performing the equivalent functions):

(a)                                  allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the registrant’s ability to record, process, summarize andreport financial information; and

(b)                                 anyfraud, whether or not material, that involves management or other employees whohave a significant role in the registrant’s internal control over financialreporting.
| Date: August 14, 2007 | By:    | /s/ John Kaiser                      |
|-----------------------|--------|--------------------------------------|
|                  |   | John Kaiser                          |
|                  |   | Chief Executive Officer and Director |

 

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