Cuscuta chinensis Lam., one of the most important traditional Chinese medicines for tonifying liver and kidney, enhances mitogen-activated protein kinases (MAPKs) activity and as a consequence induces neurite outgrowth in PC12 cells. The effect of Cuscuta chinensis Lam. extract on neurite outgrowth and its potentriated activation of MAPK were similar to that of nerve growth factor. PD98059, a specific inhibitor of MAPK, inhibited the effect of the extract on the phosphorylation of MAPK, suggesting the extract induce the PC12 cells differentiation linked to the MAPK cascade. Furthermore, the extract prevents apoptosis of PC12 cells caused by serum deprivation, indicating that it has neurotrophic factor-like activity.