BACKGROUND: It has been verified in the experiments over the past that the self-prepared Chinese herb, fuzhisan can retard natural aging in rats, suggesting that such drug acts on anti-aging.OBJECTIVE: To observe the effect of optimum effective concentration of nerve cell cultured with fuzhisan on morphological alternation of neuroblastoma SH-SY5Y cell.DESIGN: Repeated measurement.MATERIALS: The experiment was performed in Beijing Key Laboratory Room of Cerebral Aging of Xuanwu Hospital Affiliated to Capital University of Medical Sciences from June 2002 to April 2003. Self-prepared Chinese herb, fuzhisan [composed of 6 herbs, such as shichangbu (Rhizoma Acori Graminei), yuanzhi (Radix Polygalae), etc.] was co-developed by Prof.Wang De-shen from Department of Neurology of First Clinical Medical College of Harbin Medical University and Prof. Xu Xiao-yun from Department of Neurology of Shanghai Oriental Hospital. In addition, amyloid βprotein 25-35 segment and SH-SY5Y neuroblastoma were provided.METHODS: Fuzhisan of various concentrations were used for incubation of neuroblastoma SH-SY5Y cell. Thiazolyl blue (MTT), colorimetric method was used to determine the cell survival rate. Dose-effect relationship curve was drawn up to search optimum drug concentration. The cells cultured with 6-pore plate were divided into normal control, amyloid β-protein 25-35 25 μmol/L group, amyloid β-protein 25-35 25 μmol/L + fuzhisan 45×10-3 g/L groups and fuzhisan 45×10-3 g/L group. They were incubated for 24 hours to observe cell morphological alternation and determine neurosome area and axon length.ery group.length of every group: Those in amyloid β-protein 25-35 25 μmol/L group were decreased remarkably than the normal control [(505.5 ±122.36),(599.8 ±141.25) μm2; (26.0±13.97), (36.5 ±15.58) μm, (t =3.903,3.447, P=0.000)]. Those in fuzhisan 45×10-3g/L group and amyloid β-protein 25-35 25 μmol/L + fuzhisan 45×10-3 g/L group were increased remarkably than amyloid β-protein 25-35 25 μmol/L group [(918.3±178.34),(896.6 ±257.14), (505.5 ±122.36) μm2; (96.8 ±43.31), (88.3 ±30.23),(26.0±13.97) μm, (t=10.922, 14.172, P=-0.000)].CONCLUSION: With injury of amyloid β-protein 25-35, fuzhisan still enhances the survival of cultured nerve cell, manifested as promoting the increase of neurosome area and axonal extension.