Objective epithelial ovarian cancer (EOC) in early stage is difficult to diagnose. Serum indicators for stage I-II of epithelial ovarian cancer which confined to pelvic cavity were found through retrospective analysis, possible early detection methods might be found. Methods 165 patients were diagnosed as epithelial ovarian cancer at stage I-II from January 1st, 2015 to December 31st, 2019. Data was collected including age, pathological type, serum D-dimer (D-D), neutrophil to lymphocyte ratio (N/L), the platelet to lymphocyte ratio (P/L), cancer antigen 125 (CA125), human epididymis protein 4 (HE4) and diameter of the ovarian mass by ultrasound. Result D-D, CA125, HE4, ROMA, diameter, pathological type and age were significantly different in the different stage, age showed independent effect after logistical regression (P < 0.05). D-D, CA125, HE4, ROMA, diameter, age and stage were significantly different in the different pathological type, and diameter showed significant independent influence on different pathological type after binary logistic regression (P < 0.05). Conclusion CA125, HE4, ROMA, diameter of tumor, D-dimer and age were found significantly different between stage I and stage II, with age shows good effect on the diagnosis for stage II and diameter of tumor shows diagnostic value for non-serous ovarian cancer. Combined diagnosis may improve the diagnosis rate of early ovarian cancer.