Selaginella Tamariscina is widely used in the traditional oriental herbal medicine for its anti-inflammatory, anti-cancer effects. The effects of aqueous extracts of Selaginella Tamariscina (ST) on the cell viability and induction of apoptotic cell death were investigated in A549, Raw 264.7, C6-glioma. Jurkat and HL-60 cells. The cell viability after treating with extract of Selaginella Tamariscina was quantified by MTT assay method. The results showed that ST decreased the cell viability in HL-60 and Jurkat cells not in A549, Raw 264.7 and C6-glioma cells. And we also observed the chromatin condensation and DNA fragmentation in HL-60 and Jurkat cells. The enzyme activity of caspase-3, tightly regulated by an apoptosis activating complex, were markedly increased in HL-60 cells treated with the ST by dose-dependent manner. In conclusion, our results suggest that the extract of Selaginella Tamariscina may induce the selective apoptotic cell death in HL-60 and Jurkat cells via activation of caspase-3.