Objective To investigate the effects of over-expression ofhypoxia inducible factor 1α (HIF-1α) on apoptosis of PC12 cells under hypoxic injury condition mimicked by CoCl2. Methods To obtain the neural cell line over-expressing HIF-1α, the recombinant eukaryotic expression vector of pEGFPC1-HIF-1α△ODD was transfected into the differentiated PC12 cells, and pEGFPC1 was transfected into the PC12 cells as control group. PC12 cells under simulative hypoxic injury condition was constructed by CoCl2 treatment. The expression of HIF-1α was analyzed under normal and hypoxia conditions, respectively, using the method of Western blotting. Then Hoechst33342 staining, flow cytometer and caspase-3 activity detection were employed to measure and compare the cell apoptosis rates between the over-expressing HIF-1α cell line and the controls. Results We successfully constructed the model with simulative hypoxic injury to the PC12 cell line via the treatment of 50 μ mol/L or 100 μ mol/L CoCl2 for 12-24 h. The results from Western blotting illustrated that cells transfected by pEGFPC1-HIF-1α△ODD highly expressed HIF-1α under both normal and hypoxic conditions as compared with the control cells. Furthermore, Hoechst33342 staining indicated that the apoptosis rate in those transfected by pEGFPC1-HIF-1α△ODD was significantly decreased as compared with that in the control cells; the apoptosis rate in those transfected by pEGFPC1-HIF-1α△ODD (5.41±3.29)% and the control cells (8.35±2.59)% was obviously different 24 h after treatment with 50 μ mol/L CoCl2 (P＜0.05).The caspase-3 activities were significantly different between those transfected by pEGFPC1-HIF-1α△ODD (2.152±0.384) and control cells (0.921 ±0.287) 12 h after treatment with 50μmol/L CoCl2 (P＜0.05). Conclusion In the model of neural cells undergoing simulative hypoxic injury by the treatment of CoCl2, over-expression of HIF-1α can inhibit the cell apoptosis.