Objective Experimental study on the survival rate of random flap using vascular endothelial growth factor（VEGF） and bone marrow mesenchymal stem cell（MSC）. Methods MSC was isolated through the combined utilization of density gradient centrifugation and adherence screening methods. MSC was cultured and its purity and biological properties were identified. Forty Wistar rat models were established and divided into control group, VEGF group, MSC group and MSC+VEGF group. Designed 2 cm×5 cm pedicle flap on each rat’s back. The flaps were observed for 14 d after operation. On the 14th day, the rats were killed. The survival rates of random flap in each group were counted, and the histological sections were stained at the flap which was 4 cm far from the pedicle, and the number of microvascular was observed. Results 1）MSC was detected by flow cytometry, adipogenic and osteogenic induction detection. The results showed that MSC could differentiate to fat and cartilage by induction and certified that the MSC had multi-differentiation potential. 2）Immune rejection did not appear on each animal. The survival rate of random flap in control group, VEGF group, MSC group and MSC+VEGF group were 55.4%±4.4%, 70.7%±6.3%, 65.1%±7.1%, and 93.4%±9.4%, respectively. The survival rate of each experimental group was higher than control group（P
