Objective To investigate the clinical value of serum microRNA(miRNA)liquid biopsy in the diagnosis of early ovarian cancer.Methods Twenty-two fresh and frozen stage Ⅰ ovarian cancer tissues and nine adjacent normal ovarian tissues from Huzhou Maternal and Child Health Care Hospital from 2021 to 2023 were selected for this study.Differential expression of miRNA between tumors and adjacent normal tissues was analyzed using limma software package in R software.The published retrospective serum miRNA sequencing dataset GSE106817 was used to train the Logistic regression model with highly expressed miRNA in stage Ⅰ ovarian cancer,and GSE113486 and GSE31568 were used to verify the accuracy of the model.Results A total of 8 highly expressed miRNA were selected from stage Ⅰ ovarian cancer,namely miR-182,miR-183,miR-202,miR-205,miR-508,miR-509-3,miR-513B and miR-513C.The area under the curve(AUC)for diagnosing ovarian cancer in the training cohort GSE106817 was 0.89.The AUC for diagnosis of ovarian cancer in validation cohorts GSE31568 and GSE113486 was 0.85 and 0.86,respectively.Conclusion Serum miRNA liquid biopsy has high clinical value in the diagnosis of early ovarian cancer.