This study is a prospective observational clinical trial. Patients who were diagnosed and treated for the first time were enrolled and their surgical pathology was confirmed to be high-grade serous ovarian cancer. At the same time, these patients will receive first-line maintenance treatment with PARP inhibitors after traditional chemotherapy. During the trial period, patients' plasma will be collected before surgery, after chemotherapy, during targeted maintenance therapy, and during disease progression, and ctDNA-specific genomes will be detected, and clinical data will be collected over the same period. It is expected that specific ctDNA can be used to predict the efficacy of PARP inhibitors in patients with ovarian cancer, and to detect the recurrence of the disease early.