Abstract: Objective :To investigate the expression of Caspase-3 in colon carcinoma and itssignificance. Methods :The immunohistochemical LSAB method was applied to conduct the Caspase-3 determination for 79 specimen of colon carcinoma without chemoradiotherapy before operation and other related paraneoplastic tissues. Results :The positive rate of Caspase-3 in the paraneoplastic tissues and the tumorous tissues were 53.16%(42/79) and 75.95%(60/79), respectively. There was a significant difference between the groups (P<0.05). There was no obvious correlations between the expression of Caspase-3 and the age,sex, CEA level of serum, metastasis of lymphnode, depth of infiltration, as well as the Dukes staging (P>0.05),while it was related the tissular grading. The positive rate of Caspase-3 expression in the well- and the moderate-differentiation group was higher than in the poor- differentiation group (P<0.05). There was no significant difference between the 3-year survival rate in the highCaspase-3 expression group and the low Caspase-3 expression group (40.48%,47.62%;P=0.651). Conclusions : Results: Conclusion: There is a high Caspase-3 expression in colon carcinoma and it is in relation with the tissular grading, which suggesting that the Caspase-3 plays an important role in the apoptosis, incidence and development of colon carcinoma.