Objective To study the effect of exogenous basic fibroblast growth factor (bFGF) on delayed peripheral nerve regeneration. Method Transection was made on the right sciatic nerve of 50 Sprague Dawley rats. Reparing operation was made 12 weeks after transection. bFGF was injected into 25 rats as experimental group and only saline into other 25 rats as control group.All animals were observed through neuroelectro physiological examinations and histological examinations at 2,4,6,8 and 12 weeks after the reparing operation. Results In both experiment and control groups, there could be found significant nerve regeneration. In experiment group, more axons grew in the distal nerve segment at the fourth week postoperatively. The motor nerve conductive velocity,the muscle evoked action potential, the thickness of myelin, and the diameter and cross section area of regenerating axons in experimental group were better than those in the control group with a great difference. Conclusion bFGF can enhance the delayed peripheral nerve regneration.