Objective: To study the expression of the mismatch repair proteins hMSH2 and nm23 in sporadic colorectal cancer, determine any inter-relationship, and further investigate any clinical significance. Methods: Expression of hMSH2 and nm23 proteins was assessed in 87 colorectal cancer tissues by SP immunohistochemistry, with analysis of survival using follow-up data. Results: In the sporadic colorectal cancer tissues, nm23 protein expression appeared independent of the histological type (P>0.05), but correlated with the invasion depth and lymphatic metastasis (P<0.05). In contrast, hMSH2 protein expression was not significantly correlated with these clinicopathologic features (P>0.05), although it positively correlated with that of nm23 protein in the sporadic colorectal cancers (rs=0.635, P<0.05). Combined expression of the two was found to be related with invasion depth, lymphatic metastasis and prognosis of sporadic colorectal cancer (P<0.05). Conclusion: nm23 protein level was related with the degree of malignancy, and could be used as an index to predict the invasion and metastasis potential. The expression of hMSH2 protein is positively correlated that of nm23 protein, and the combined expression of the two has certain guiding significance for the prognosis of sporadic colorectal cancer.