PD-L1，B7-H3 and B7-H4 can bind to the receptors of T cells，leading to the inhibition of the proliferation and overactivation of T cells. PD-L1，B7-H3 and B7-H4 play negative modulation in cellular immune response and have been confirmed to be closely associated with immunogenicity. These three molecules do not express in normal ovary tissue but express strongly in ovarian cancer tissue，which enable the three molecules to be new tumor markers for diagnosing primary ovarian epithelial cancer. These three molecules are assumed to function in occurring and malignant transferring of ovarian cancer，and are valuable for diagnosing ovarian cancer in early stage and targeting therapy.