<p><b>OBJECTIVE</b>To investigate the effect of recombinant adenovirus-mediated triple mutant of hypoxia inducible factor-1alpha (Ad-HIF-1alpha-564/402/803) in modulating angiogenesis in vitro.</p><p><b>METHODS</b>The recombinant adenoviruses Ad-lacZ, Ad-Null, Ad-HIF-1alpha-nature, and Ad-HIF-1alpha-564/402/803 were amplified in HEK293A cells and purified by ultracentrifugation in CsCl step gradient solutions, and the adenoviral titer was determined by end-point dilution assay. The recombinant adenovirus was confirmed by PCR and DNA sequence analysis, and the infection efficiency was observed by X-gal staining. Human microvascular endothelial cells (HMVECs) were infected with Ad- HIF-1alpha-564/402/803, Ad- HIF-1alpha-nature, or Ad-Null to compare the number of capillary-like tube structures in vitro. The effect of Ad- HIF-1alpha-564/402/803, Ad-HIF-1alpha-nature, and Ad-Null on angiogenesis was evaluated using a chick embryo chorioallantoic membrane (CAM) model.</p><p><b>RESULTS</b>PCR and gene sequencing suggested the correct construction of the recombinant adenovirus HIF-1alpha, and the adenoviral titer reached 1011-1012 PFU/ml. Infection of the hMVECs with Ad-HIF-1alpha-564/402/803 at the optimal multiplicity of infection of 100 pfu/cell resulted in a significantly greater number of capillary-like tube structures than infection by Ad-HIF-1alpha-nature and Ad-Null (P=0.000). Ad-HIF-1alpha-564/402/803 group showed significantly higher microvessel density than Ad-HIF-1alpha-nature, Ad-Null, and PBS groups, with also higher angiogenesis area to CAM area ratio (P=0.01, 0.000, and 0.000, respectively).</p><p><b>CONCLUSION</b>The triple mutant Ad-HIF-1alpha-564/402/803 can obviously promote the formation of capillary-like tube structures in vitro and modulate angiogenesis in the CAM model, suggesting the capacity of Ad-HIF-1alpha-564/402/803 in promoting angiogenesis under normoxic condition.</p>