Pioglitazone is the oral anti-diabetic drug and it needs insulin to exert its effects and it reduces insulin resistance in environment. This drug is a potentand specific agonist for PPAR. The purpose of this study is testing the effect of different doses of pioglitazone on the ovulation hormones. This experiment is done in a completely randomized block design and compared with Duncan test. In this experiment 16 sheep with an average of 3 to 4 years and weighing about 60 kg were used. Ewes were randomly divided into 4 groups. The control group received no treatment, treatment1received 10mg of pioglitazone, treatment2 received 20 mg of pioglitazone, treatment 3 received 30 mg of pioglitazone. The pioglitazone treatment was given orally for 42 days. The first blood sampling was performed 2 times first blood sampling was before treatment and the second was after the forty-second days after ram up. In this study, serum concentrations of LH, FSH, estrogen, progesterone, insulin, leptin, cholesterol and triglycerides were measured. The results of this study shows that serum levels of estrogen, progesterone, 1, 2 and 3 compared to control treatments were significantly different (P<0.05). Treatment1of FSH was significantly different compared to control group (P<0.05).Treatment 1insulin was significantly different compared to control group (P<0.05). Treatments1, 2and 3of leptin were significantly different compared to control group (P<0.05).The results of this experiment showed that pioglitazone may have significant effects on hypothalamic- pituitary and ovarian hormones.