Objective To investigate the expression and location of ras and rab interactor 1（RIN1） in ovarian cancer cell lines and analyze the expression and clinicopathological significance of RIN1 protein in ovarian cancer tissues. Methods Expression and location of RIN1 protein in normal human ovarian epithelial cell line and three ovarian cancer cell lines（OVCAR3， SKOV3 and HO8910） were detected by Western blotting assay as well as the expression of RIN1 protein in 17 cases of normal ovarian tissues and 91 cases of ovarian tumor tissues. Results RIN1 protein in ovarian cancer cell lines OVCAR3，SKOV3 and HO8910（0.3641±0.0614， 0.6454±0.0835 and 0.7925±0.1491）were higher than that in normal human epithelial cell（0.0679±0.0269）with statistical significance（P＜0.05），and RIN1 protein localized chiefly in the cytoplasm of ovarian cancer cell lines. The expressions of RIN1 protein in 37 benign ovarian tumors，10 borderline ovarian tumors and 44 malignant tumors were 0.3456±0.1870， 0.5587±0.2138 and 0.7236±0.2232，much higher than that in 17 normal ovarian tumor tissues（0.1284±0.0982） with significance（P＜0.01）. The expression of RIN1 increased with the severity of ovarian tumors. The expression of RIN1 protein was significantly increased with the progression of surgical pathological stage and tumor differentiation. Conclusion RIN1 protein was overexpressed in ovarian cancer cells and localized chiefly in the cytoplasm of cancer cell.Overexpression of RIN1 was associated with tumor progression in ovarian cancer， and RIN1 may act as a new tumor marker for diagnosis and a new therapeutic target in patients with ovarian cancer.