Abstract: Objective To explore the apoptosis gene and protein expressions of colon smooth muscle cell in diabetic colon dysmotility. Methods Thirty-six male Sprague-Dawley(SD) rats were randomly divided into 4 groups which included control 6w and 10w group、DM 6w and 10w group (n=9). Fasting blood glucose(FBG)、gastrointestinal transit rate and the serum level of fasting insulin (FINS) were detected, and the changes in the colon smooth muscle were examined by HE staining. The mRNA expression levels of BAX、BCL-2 and CASPASE-3 in the colon smooth muscle cells were determined by real-time quantitative PCR(RT-qPCR). Immunohistochemistry was used to detect the protein expression of CASPASE-3.Results ⑴ FBG of DM group was significantly higher than that of the control group. Gastrointestinal transit rate and FINS of DM group were significantly lower than those of the control group. The colon smooth muscle in DM group became thinner than that in the control group. The mRNA expression levels of BAX and CASPASE-3 in DM group were higher than those in the control group and the mRNA expression level of BCL-2 in DM group was lower than that in the control group. The protein expression of CASPASE-3 in DM group was higher than that in the control group(control 6w and 10w group are 4694±807、4711±812；DM 6w and10w are 6974±952、12474±967）,( P＜0.01).⑵ The changes above are more significant in DM 10w group compared with DM 6w group,(P＜0.05). Conclusion Diabetic colon dysmotility may be closely associated with the changes of apoptosis gene and protein expressions of colon smooth muscle cell, and the apoptosis may become more significant with disease developing.