In order to investigate focal flushing dose radiation effect on the generation, differentiation and gene expression of bone marrow stromal cells the femoral head of rats was irradiated at 30 Gy by ,137,Cs γ-rays (dose rate: 0.83 Gy/min). Then the bone marrow stromal cells (BMSCs) was cultured. The ability of proliferation and colony formation was observed and the expression level of Cbf-α1, PPAR-γ, VEGF-a and KDR was detected by RT-PCR technology in two weeks later. It has been found that after partly irradiated by ,137,Cs γ-rays the proliferation and the number of colony of BMSCs in irradiated group decreases obviously meanwhile the expression level of Cbf-α1, PPAR-γ and VEGF-a in irradiated BMSCs obviously decreases by 18.98 %, 9.46 %, 57.34 % and 5.56 % respectively compared to the normal BMSCs (,p,<,0.05). It shows that the focal great radiation could damage the BMSCs and depress the generation, differentiation and the expression of the related genes obviously.