【Objective】To investigate the role SPAG5 play in ovarian adenocarcinoma cell mitosis，Taxol sensitivity and ovarian high grade serous carcinoma patients?? prognosis.【Methods】Transient knockdown of SPAG5 in SKOV3 cell were performed， and MTT assay and cell cycle flow cytometry assay were carried out. IHC staining of SPAG5 protein in 110 high grade serous carcinoma patients′ tumor tissues were performed，and the expression were analyzed with clinical data and prognosis. Finally，SPAG5 were knocked down in OVCAR3 A2780 and SKOV3 cells followed by 0.5μM Taxol treatment，MTT assay were performed to detect cell viability.【Results】SPAG5 knockdown inhibited cell mitosis of ovarian adenocarcinoma cell SKOV3 by G2/M arrest. High grade serous carcinoma patients after neoadjuvant chemotherapy gained the expression of SPAG5. Patients without neoadjuvant chemotherapy with low SPAG5 expression have poor progress free survival，especially in early stage patients. Patients with low SPAG5 expression also have poorer overall survival，but the difference was not statistically significant. Furthermore，SPAG5 knockdown in OVCAR3 A2780 and SKOV3 cells reduced Taxol sensitivity. 【Conclusion】 SPAG5 regulated cell mitosis and promoted cell proliferation in ovarian adenocarcinoma cell lines. Expression of SPAG5 in patients?? tumor tissues predicted patients?? prognosis and Taxol sensitivity. As the results，individualized treatment of high grade serous carcinoma patients is necessary.