Abstract： Objective To study the effect of Angiotensin Ⅱ (Ang Ⅱ) on the expression and protein secretion of vascular endothelial growth factor (VEGF) in human bone marrow stromal cells (hBMSCs) derived osteoblasts. Methods hBMSCs were isolated,cultured and induced to differentiate into osteoblasts.The cells were identified by alkaline phosphatase (ALP) staining.The hBMSCs induced for 14 days were divided into 5 groups ( n =3) and treated by Ang Ⅱ at concentrations of 50,100,150 and 200 nmol/L to determine the optimal one.The hBMSCs induced for21 days were divided into 5 groups ( n =6) and treated by Ang Ⅱ at the optimal concentration for 0,6, 12,24,48 hours.The level of mRNA VEGF was determined by SYBRGREN fluorescent quantitation and the level of VEGF protein in the medium was measured by ELISA.Results When the hBMSCs were cultured in the conditioned culture medium,most of the ALP staining was positive.The expressions of mRNA VEGF in the hBMSCs treated by Ang Ⅱ at concentrations of 0, 50, 100, 150 and 200 nmol/L were respectively 1.000±0.000,2.304±0.315, 4.336t0.400,5.573 ± 0.608 and 5.492 ± 0.460. There were significant differences regarding the expression levels respectively between the first 2 concentrations and the Iatter 3 concentrations ( P ＜ 0.05).The concentration of 150 nmol/L was used as the optimal one to treat Ang Ⅱ.The expressions of mRNA VEGF in the hBMSCs treated by Ang Ⅱ at the optimal concentration for 0,6,12,24,48 hours were respectively 1.000 ± 0.000,1.984 ± 0.160,4.372 ± 0.378,5.573 ± 0.586 and 4.994 ± 0.445.There were significant differences regarding the expression levels respectively between the first 2 time points and the latter 3 time points ( P ＜0.05).The protein secretions by VEGF induced by Ang Ⅱ at the optimal concentration for 0,6,12,24,48hours were increased in a time-dependent manner. Conclusion Incubation of hBMSCs derived osteoblasts with Ang Ⅱ may induce a rapid increase in both VEGF mRNA expression and protein synthesis.