Abstract: Objective To observe the effect of peripheral nerve Wallerianian degeneration at different time points on homing of bone marrow mesenchymal stem cells (BMSCs). Methods Seventy-two adult male SD rats weighing 220-250 g were randomly divided into 6 groups (n=12) according to their weight. Each group was divided into group A and group B according to the injected cells and drugs. Rats in group A (n=6) were injected with BMSCs and saline via their tail vein and those in group B (n=6) were injected with BMSCs and AMD3100. Their sciatic nerve was cut off along the inferior border of piriformis under aseptic condition with its proximal end ligated and distal end excluded. The rats in group A were injected with BMSCs and saline 1, 3, 7, 14 days, 1 and 2 months after sciatic nerve transaction and those in group B were injected with BMSCs and AMD3100. Three days after injection, the effect of peripheral nerve Wallerianian degeneration on homing of BMSCs was observed through the in vivo imaging system. Results The aggregation of BMSCs in sciatic nerve with Wallerianian degeneration increased at fi rst and then decreased with the prolonged time, and was weaker in group B than in group A during the early Wallerianian degeneration of sciatic nerve (1-3 d). Conclusion BMSCs can migrate into the peripheral nerve tissue with Wallerianian degeneration. Their homing increases at fi rst and then decreases with time, which is regulated by the SDF-1-CXCR4 axis and inhibited by the CXCR4 speci fi c antagonist AMD3100.