Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders affecting women of reproductive age. Cangfu Daotan Decoction (CFDTT) is one of the prescriptions in the stagnation of obesity-type PCOS. Our previous study showed that CFDTT treatment of obese PCOS was correlated with organic anion transporting polypeptides (OATPs). Here, we studied the effects of CFDTT on obese PCOS and its underlying mechanism. We built an obese PCOS rat model and treated the rats with CFDTT. Then, we detected the serum levels of TCHO, TG, LDL-c, HDL-c, luteinizing hormone (LH), follicle stimulating growth hormone (FSH), testosterone (T), estradiol (E2), IL-1β, IL-6, and TNF-α in each group and adopted RT-PCR, western blotting and immunohistochemical staining to investigate the effects of CFDTT treatment on the expression of OATP2B1 and OATP3A1 in ovarian and uterine tissues. In addition, we compared the pregnancy outcomes of each group. We found that CFDTT decreased the serum levels of TCHO, TG, LDL-c, LH, T, IL-1β, IL-6, and TNF-α and increased the levels of HDL-c, FSH and E2 in a dose-dependent manner. CFDTT could induce the expression of OATP2B1 and OATP3A1 in ovarian and uterine tissues. Moreover, CFDTT could improve pregnancy outcomes. These data suggested that the therapeutic mechanism of Cangfu Daotan Decoction on PCOS may be correlated with regulating lipid metabolism, sex hormone secretion and the inflammatory response and increasing OATP2B1 and OATP3A1 expression. Cangfu Daotan Decoction can be developed as a PCOS treatment drug. Copyright © 2020 Elsevier Inc. All rights reserved.