The tumor necrosis factor (TNF) gene expression in ovarian tumor was observed with digoxigenin labeled TNF-alpha cDNA probes and in situ hybridization technique. 54 cases of fresh biopsies of the ovarian tumor and 10 cases of normal ovaries were snap frozen sectioned. The results showed that the average positive rate of TNF gene expression in some ovarian cells and tumor infiltrating lymphocytes (TIL) was higher than that in the borderline and benign tumor cells and TIL. The more advanced clinical stages, the higher does positive rate of TNF gene expression in the cancer cell and the smaller dose in the TIL. It was appeared that TNF gene expression of the tumor cells and TIL was connected with clinical stage and tissue typing of ovarian tumor. The data suggested TNF gene expression of cancer cell might play a role in the progress of ovarian cancer and as a marker of the advanced malignancy tumors. In addition, TNF gene expression of the TIL might mark the restinced state of the host immunology.