Abstract: Objective To determine the expression of claudin-23 in colorectal cancer and paracarcinoma tissues, and its effects on the proliferation and migration of colorectal cancer cells. Methods Six pairs of samples of colorectal cancer and corresponding paracarcinoma tissues were collected from the West China Hospital of Sichuan University. Quantitative real time PCR was performed to determine the expression of claudin-23 in the tissue samples. Colorectal cancer cell lines with stable overexpression of claduin-23 were constructed using lentivirus. CCK-8 and migration assays were conducted to identify the effects of claudin-23 on cell proliferation and migration. Results The expression of claudin-23 in colorectal cancer tissues decreased compared with their adjacent normal tissues (P<0.05). claudin-23 decreased cell adhesion and increased cell proliferation in HCT15 cells. RKO and HCT15 cells with over expressed claudin-23 had increased ability of migration. Conclusion claudin-23 facilitates the migration ability of colorectal cancer cells and may participate in the metastasis of colorectal cancer.