Abstract: The protective effects of nerve growth factor (NGF) on peripheral nerve injury and sensory neuron growth were studied in three models: peripheral sympathetic nerve injury induced by intraperitoneal injection of 6-hydrodopamine (6-OHDA), mechanically injured ulnar nerve and cultured dorsal root ganglion (DRG) of newborn rats in vitro. The results indicate that NGF dosedependently increased norepinepherine content in mouse submandibular gland and cell numbers of C₇ (seventh cervical vertebra), T₁ (first thoracic vertebra) dorsal root ganglion in rabbits, and also dramatically promoted the growth of neuronal projections in cultured DRG. These results suggest that NGF has significant neuroprotiveaction in peripheral nerve injury and a strong neuronutrition on sensory neuron.