Objective: To investigate the correlation of clinicopathologic features of deficient mismatch repair (dMMR) defects in colorectal cancer and vessel density. Methods: Samples of colorectal cancer patients admitted to Guangzhou Red Cross Hospital from January 2016 to December 2018 were selected. Immunohistochemistry was applied in 101 samples to detect four MMR proteins (including MLH1, MSH2, MSH6, and PMS2) so as to estimate dMMR. CD34 and D2-40 were used to detect microvessel density and microlympatic density. Results: In 101 cases of cancer tissue, 18 (17.8%) samples were detected as dMMR defects, which was characterized by tumor located in the right colon, with the maximum diameter less than 5 cm, higher proportion of poor differentiation and lower rate of lymphatic metastasis (all P<0.05). dMMR had no relationship with depth of tumor invasion and distant metastasis. The dMMR patients had lower microvessel and microlympatic density. There was positive correlation between MMR protein expression and microvessel and microlympatic density (all P<0.05). Conclusion: dMMR is closely associated with tumor location, tumor size and tumor differentiation. The reduced rate of lymphatic metastasis in dMMR is correlated with lower density of microvessel and microlympatic density.