OBJECTIVE: To clarify the character of nerve growth factor (NGF) in the denervated red and white muscles and the relationship between the amount of NGF and sensitive neurotrophism of denervated red and white muscles. METHODS: The model of the denervated gastrocnemius and soleus was made by clipping the sciatic nerve of Wister rats. The immunohistochemistry was taken to measure the amount of NGF in muscles, and the neurotrophism of extracts of muscles was tested with culture of dorsal root ganglions at the 1st, 3rd, 7th and 14th days after injury. RESULTS: The amount of NGF in denervated gastrocnemius and soleus decreased, especially in soleus. The neruotrophism of the extracts of the two kinds of denervated muscles did not decrease; on the contrary, it increased after a week after injury. CONCLUSION: The injury of peripheral nerves causes the amount of NGF in the target tissues to increase, but the change is different between the denervated muscles; the neurotrophism of the extracts of musclesis determined by all kinds of neurotrophic factors, and can not be explained by a single factor.