Abstract: Objective To observe the influence of platelet-rich plasma (PRP) on the back flap neovascularization in diabetic rats and analyze the changes of the levels of vascular endothelial growth factor(VEGF),stromal cell-derived factor(SDF-1) and chemokine growth factor receptor(CXCR4). Methods Total 100 SD rats were randomly divided into five groups with 20 in each group.The reserve group was prepared PRP and platelet poor plasma(PPP),the control group was normal feed,and the other three groups were made diabetic pathological model.After model success the back flaps were prepared.PRP and PPP group were treated by PRP and PPP intervene locally.After 1 week,the angiogenesis was observed,VEGF level was measured by ELISA and SDF-1 and CXCR4 were detected by immunohistochemistry assay. Results When compared to control group,the flap survival rates of model group and PPP group were reduced,new blood vessel number and VEGF level were reduced,and SDF-1 and CXCR4 expression were reduced.The differences were statistically significant(P<0.05).Compared to model group and PPP group,flap survival rate of PRP Group was higher,the new blood vessel number and VEGF level were higher,and SDF-1 and CXCR4 expression were higher.The differences were statistically significant(P<0.05). Conclusion PRP can improve the local and systemic VEGF level of diabetic rats,increase the expression of SDF-1 and CXCR4,and promote angiogenesis,which might be the mechanisms for promoting the healing skin flap.