Objective: To evaluate the therapeutic effects of bone marrow-derived endothelial progenitor cells (EPC) transplantation in the early phase of acute renal ischemia reperfusion injury（IRI）in rats and their impact on tubular epithelial cell apoptosis. Method: Bone marrow-derived monocytes cells were isolated from the femurs and tibiae of male SD rats with ficoll density gradient centrifugation. Induced differentiation into EPC in vitro. Male SD rat were randomly divided into 3 groups, 10 in each group: transplanted group, control group and sham-operated group, 10 in each group. Rats of transplanted group were induced acute renal IRI by clamping bilateral renal arteries for 45 minutes, then transplanted EPC labeled with CM-Dil immediately after the resumption of circulation in kidney. The rats of control group were induced acute renal IRI and then infused with saline instead. The sham operated rats were infused with EPC labeled with CM-Dil like transplanted group after shame operation. Renal function of three groups was detected at different time points. 72 hours after surgery, all rats were sacrificed. Kidney morphology, apoptosis were observed. And the homing of EPC in IRI kidney was observed by fluorescence microscope. Results: 72 hours after transplantation, EPC derived CM-Dil positive cell were detected at the junction of the cortex and medulla of the in the renal tissues of transplanted rats. Compared with control group, the renal functional and structural damage were significantly ameliorated (P<0.05), tubular epithelial cell apoptosis was reduced significantly in transplanted group (P<0.01). And the expression levels of VEGF (P<0.05) were also increased greatly in transplanted group. Conclusions: Bone marrow-derived EPC transplantation is curative for acute renal IRI in rats. EPC might ameliorate renal morphology and function after renal IRI by reducing tubular epithelial cell apoptosis.