Objectives : This work was designed to investigate the effect of The root of Achyranthes japonica Nakai (AJN) water extract on serum deprivation reperfusion-induced apoptosis in PC-12 cells and transient middle cerebral artery occlusion (tMCAO)-induced ischemic brains of rats. Methods : Apoptosis in PC12 cells was induced by serum deprivation and reperfusion. The cells were treated with AJN water extract at doses of 0.5 and 1.0 mg/ml for 24 hr after inducing the apoptosis. Cell viability was determined by WST-1 assay. The expression of caspase-3 protein was determined by Western blot. Ischemic brains were prepared from tMCAO-induced ischemic rats after oral administration with AJN at dose of 50 and 100 mg/kg, and then brain infarction was measured by TTC staining. Results : AJN significantly increased the cell viability in apoptocic-induced PC-12 cells, and also decreased the expression of caspase-3 protein. Furthermore, the administration of AJN significantly inhibited tMCAO-induced brain infarction in rats. Conclusions : Our results suggest that AJN extract has a neuroprotective property via suppressing the apoptosis in PC12 cells and the infarction of ischemic brains.