Abstract: To investigate the effect of cisplatin on the induction of apoptosis in colonic carcinoma. Methods: A 2-hour exposure of SW1116 human colonic carcinoma cell line in index phase of growth to various levels of cisplatin resulted in the apoptosis,which is detected by gel electrophoresis of DNA,stainig with AO and electronic microscopy. Results:The apoptosis had occured in SW1116 was confirmed by electronic microscopy and gel electrophoresis of DNA. Morphologically,apoptotic cell death is characterized by cell shrinkage and aggregation of the chromation into dense,often crescent—shaped masses under the nuclear membrane. The staining with AO and fragmentation of DNA showed that the rate of apoptosis was dependent on the dose of cisplatin. A percentage of the total apoptotic cell number,compared with control group, has significant difference (P＜0.05). Conclusion :Cisplatin may induce and promote the apoptosis of colonic carcinoma.