Salvianolic acid B is isolated from Salvia miltiorrhiza,the root of which is widely used as a traditional Chinese medicine to treat stroke.However,little is known about how salvianolic acid B influences growth characteristics of neural stem cells (NSCs).The purpose of the present study was to evaluate the effects of salvianolic acid B on proliferation,neurite outgrowth and differentiation of NSCs derived from the cerebral cortex of embryonic mice using MTT,flow cytometry,immunofluorescence and RT-PCR.It was found that 20 μg mL·1 and 40 μg mL·1 salvianolic acid B had similar effects on proliferation of NSCs,and a suitable concentration of salvianolic acid B increased the number of NSCs and their derivative neurospheres.The growth-promoting activity of salvianolic acid B was dependent on and associated with an accumulation in the G2/S-phase cell population.Salvianolic acid B also promoted the neurite outgrowth of NSCs and their differentiation into neurons.The mRNA for tau,GFAP and nestin were present in differentiating neurospheres induced by salvianolic acid B.However,high-level expression of tau mRNA and low-level expression of GFAP mRNA was detected in differentiated cells,in contrast to the control conditions.This collective evidence indicates that exogenous salvianolic acid B is capable of promoting proliferation of neurospheres and differentiation towards the neuronal lineage in vitro and may act in the proliferation of NSCs and may promote NSC differentiation into neuronal cells.