To investigate the effects of Shenwu capsule (SW) and its component tetrahydroxystilbene glucoside (TSG) on the expression of neurotrophic factors in lumbar spinal cord of aged rats. SD rats were divided into 6 groups, including 6-months-old group, 24-months-old group, 24-months-old + low dose SW (0.8 g x kg(-1)), high dose SW (1.6 g x kg(-1)), low dose TSG (0.03 g x kg(-1)) and high dose TSG (0.06 g x kg(-1)). Western blot was used to detect the expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), gliacyte-derived neurotrophic factor (GDNF) in the lumbar spinal cord of rats. Compared with 6-month-old young rats, the expression of NGF, BDNF and GDNF in the lumbar spinal cord was significantly decreased in the 24-month-old rats (P < 0.05, P < 0.01). Intragastric administration of SW for 3 months obviously enhanced the expression of NGF, BDNF and GDNF in the lumbar spinal cord of aged rats (P < 0.05, P < 0.01), and TSG significantly enhanced the expression of GDNF (P < 0.05). SW capsule and its component TSG elevated the expression of neurotrophic factors in the lumbar spinal cord of aged rats, suggesting that these drugs may retard aging process of the spinal cord.