Objective:To study the effects of pigment epithelium derived factor (PEDF) on the expression of vascular endothelial growth factor(VEGF) in hypoxic human bronchial epithelial(HBE) cells,and to determine whether the expression of VEGF is associated with the expression of hypoxia-inducible factor (HIF)-1α in cultured cells. Methods:The cultured HBE cells between 3rd to 7th generations were used in the study,and 100 -滋mol/L cobalt (II) chloride hexahydrate (CoCl2) were used to simulate anaerobic condition. There were four groups in the study:control (group A),CoCl2 100 -滋mol/L(group B),CoCl2 100 -滋mol/L +PEDF 50 ng/ml (group C) and CoCl2 100 -滋mol/L +PEDF 200 ng/ml (group D). The expression of HIF-1α and VEGF mRNA were detected by real-time polymerase chain reaction (RT-PCR). The expression of VEGF in the different groups were examined by enzyme-linked immunosorbent assay(ELISA) and Western blot. Immunofluorescence (IF) was performed to test the expression of HIF-1α in cytoplasm and cytoblast. Results:①The level of VEGF mRNA was significantly elevated(8.56 ± 0.67)-fold in group B compared with that in group A (P < 0.01),which was decreased in group C and group D (P < 0.01) compared with that in group B. Compared with group A,the level of HIF-1α mRNA was elevated significantly in group B (P < 0.01). However,there were no significant differences of HIF-1α mRNA level among group B,C and D. ②The concentration of VEGF protein in cell cultural supernatant was higher in group B [(1 370.10 + 42.98)pg/ml,P < 0.01] than that in group A [(670.00 + 23.35)pg/ml]. The levels of VEGF in group C [(816.19 + 37.05)pg/ml] and group D [(646.47 + 22.70)pg/ml] were decreased compared with group B (P < 0.01). ③The level of VEGF protein detected by Western blot in group B was (3.99 ± 0.37)fold of that in group A (P < 0.01),and there were significant differences between group B and the other two groups (group C and D,P < 0.05). ④ IF showed that the level of HIF-1αprotein and the nuclear translocation of HIF-1α in group B were significantly increased compared with those in group A and D. Conclusion:PEDF could inhibit the overexpressed VEGF expression in hypoxic HBE cells,and this effect may be related to PEDF-regulated HIF-1α.