Objective To study the antitumor activity of extract from Salvia plebeia and investigate whether the extract induce apoptosis of K562 cells. Methods The aqueous, petroleum ether, dichloromethane (CH2Cl2), ethyl acetate, and butanol extracts were prepared from the aerial parts of 5. plebeia. Taking fluorouracil as reference, the cytotoxic activities of these extracts on HeLa, A549, SGC-7901, HCT-116, K562, LoVo, DU-145, and HepG2 cells were evaluated. To clarify the apoptosis of K562 cells induced by CH2Cl2 extract, the methods of Hoechst 33258 staining, flow cytometry assay, and DNA ladder assay were investigated. Results The CH2Cl2 extract showed the most potent cytotoxic effect against K562 cells, with an IC50 < 15 μg/mL for 3 d treatment. The characteristic apoptotic symptoms such as DNA fragmentation and chromatin condensation were also observed in the K562 cells. Conclusion The CH2Cl2 extract from S. plebeia may inhibit the cancer cell proliferation by inducing cell apoptosis.