Abstract: Objective：To investigate the expressions of B7-H4 and B7-H6 in ovarian tumor tissues and related clinicopathological characteristics. Methods：A total of 101 ovarian tumor specimens from Tongji Hospital Affiated to Tongji University were collected, among which 43 cases were benign and 58 cases were malignant. The expressions and distributions of B7-H4 and B7-H6 in ovarian benign and malignant tumors were investigated by immunohistochemical staining. Chi-square test and nonparametric rank sum test were used to analyze the correlation between B7-H4 and B7-H6 protein expressions and clinicopathological parameters. Results：Immunohistochemical results showed that 82.76% (48/58) of malignant tumors expressed B7-H4 and 79.31% (46/58) of malignant tumors expressed B7-H6, respectively. While in benign ovarian tumors, there were 13.95% (6/43) and 16.28% (7/43) samples that expressed B7-H4 and B7-H6. The expressions of B7-H4 and B7-H6 proteins in ovarian malignant tumors is significantly higher than that in benign ovarian tumors (P<0.05). B7-H4 and B7-H6 proteins were mostly distributed in the cytoplasm and cell membrane. Moreover, the expression levels of B7-H4 and B7-H6 proteins in ovarian cancers were tightly correlated with the patients’ age, histological type of tumors, and p53 expression (P<0.05). Conclusions：The high expressions of B7-H4 and B7-H6 proteins in ovarian malignant tumors indicates their potential roles in the occurrence and progress of ovarian malignant tumors.