Objective To establish a stable rat model of non-obese polycystic ovary syndrome(PCOS)with clinical characteristics.Methods Dehydroepiandrosterone(DHEA)was used to establish a PCOS rat model by subcutaneous injection.Three-week-old female SD rats were divided into a normal group,6 mg/kg DHEA model group,and 60 mg/kg DHEA model group.The model groups were subcutaneously injected with the corresponding dose of DHEA daily,while the normal group was subcutaneously injected with glycerol daily for 21 consecutive days.The model was evaluated with ovarian histopathology as the gold standard to determine the optimal dosage of DHEA to induce a PCOS rat model.On this basis,the optimal DHEA modeling dose was selected,and stop and continue modeling groups were set up to observe the model for 28 days and evaluate its maintenance.The stop modeling group was no longer given DHEA,and the continued modeling group was subcutaneously injected with 60 mg/kg DHEA every 48 h.The evaluation indicators included body mass,estrous cycle,fasting blood glucose,serum insulin,histopathologic morphology of the ovaries,and serum sex hormone levels.Results(1)Compared with the normal group,the 6 mg/kg and 60 mg/kg DHEA model groups showed no significant difference in body mass,and their estrous cycles were irregular.There were more cystically dilated large follicles in the ovaries;fewer mature follicles;reduced layers of granulosa cells,which were arranged in a sparse and disorganized manner;and fewer lutea in the 6 mg/kg and 60 mg/kg DHEA model groups than the normal group.Furthermore,serum T and E2 levels were significantly higher in the 60 mg/kg DHEA model group(P＜0.05)than the normal group.(2)The stop modeling group(A2 group)resumed regular estrous cycles after 2 weeks,various growth follicles and corpora lutea were observed in the ovarian tissues,the number of cystic follicles was reduced,the number of granulosa cell layers increased,mature follicles were visible,oocyte morphology was locally intact,and the levels of E2 and AMH were reduced compared with the normal group(A1 group)(P＜0.05).(3)The continue model group(B2 group)was in the late stage of estrous cycle for a long period,and there were more large follicles with cystic dilatation,fewer mature follicles,fewer layers of granulosa cells with a sparse and disordered arrangement,and significantly fewer corpus lutea in the ovaries compared with the normal group(B1 group).The levels of serum LH,LH/FSH,and T were elevated(P＜0.05).Conclusions Subcutaneous injection of 60 mg/kg DHEA for 21 consecutive days can be used to successfully construct a non-obese PCOS rat model that possesses clinical characteristics.Subcutaneous injection of 60 mg/kg DHEA every 48 hours maintains the stability of the model.