Rats were treated intraperitoneally with ganglioside (Gan) 10, 20 and 50 mg·kg 1 ·d 1 respectively for 8 d, then the sciatic nerve was crushed using a standardized procedure. In another group, the rats were treated with Gan 50 mg·kg 1 ·d 1 for 8 d before and 6 d after nerve damage. In the d 7 after nerve damage, histological evaluation of the sciatic nerve transverse sections 1 cm distal to the nerve crush was performed by means of an image analyzer, and the number of nerve fibers was recorded. It was found that the number of fibers was obviously higher in the 50 mg·kg 1 treated group than that in the control group (normal saline treated); 20 mg·kg 1 Gan had a weaker effect and the 10 mg·kg 1 Gan had no effect. The results of the group treated with 50 mg·kg 1 Gan before and after nerve damage were similar to that of the group treated with 50 mg·kg 1 Gan before nerve damage alone. The above results indicate that Gan which is injected into rats before nerve damage can be stored in the dynamic Gan pool in the body. When the nerves are damaged, those Gan can nourish the nerve, join the process of nerve repair, and prevent the nerve degeneration. The above results also mean that the enough amount of Gan stored in the body before nerve injury is important for the prevention of Wallerian degeneration.