Objective To study the effects of JS-K on proliferation and apoptosis of HCT116 human colon cancer cells. Methods HCT116 cells were treated with different concentrations of JS-K for 48 hours, and cell proliferation was accessed by MTS assay; the effect of JS-K on HCT116 cell cycle was detected by PI single staining flow cytometry; and the effect of JS-K on HCT116 cell apoptosis was detected by annexin V-FITC / PI double staining flow cytometry; cell morphology was observed by staining with Texas Red-X phalloidin; the expression levels of Bcl-2 family genes were detected by quantitative reverse transcription polymerase chain reaction (qRTPCR). Results MTS results showed that JS-K significantly inhibited the proliferation of HCT116 cells in a concentration- and time-dependent manner (P < 0.05). Flow cytometry analysis of PI-stained cells showed that the G2/M phase arrest was induced by JS-K (P < 0.05). In addition, flow cytometry analysis of Annexin V-FITC/ PI double stained cells indicated that JS-K induced late apoptosis of HCT116 cells (P < 0.05). Furthermore, JS-K treatment altered the cytoskeleton morphology, microfilament structure and distribution. qRT-PCR results showed that with the increase of JS-K concentration, the expression levels of proapoptotic gene Bax, Bik, Bim and Puma mRNA were up-regulated, however, the anti-apoptotic gene Mcl-1 mRNA expression levels was down-regulated (P < 0.05). Conclusions JS-K significantly inhibit the proliferation of HCT116 human colon cancer cells, regulate the expression levels of Bcl-2 family genes, induce G2/M arrest and further promote late apoptosis.