The present study was carried out to investigate the effect of gonadotropin administration on blood ovarian steroid hormone in angora rabbit. Mature angora rabbits were primed for superovulation with PMSG 100IU. Eighty hours later, the rabbit were induced to ovulate with HCG 100IU. In exp 1, blood progesterone and estradiol of superovulated does were measured by radiommunoassay. Blood progesterone concentration at 93, 99, 102 and 114 hours after HCG injection were 12.9$pm$0.5, 34.8$pm$5.1, 12.2$pm$2.7 and 43.4$pm$5.8ng/ml, respectively. Mean progesterone concentration of blood collected at 99 and 114 hours after HCG injection(p<0.05). However, mean blood estradiol concentration was not changed. In exp 2, superovulated does were unilaterally ovariectomized at 96 hours after HCG injection. Blood progesterone concentration was tend to be decreased after ovariectomy. Nosignificant changes in blood estradiol concentration was observed after ovariectomy. In exp 3, superovulated does were bilaterally ovariectomized at 96 hours after HCG injection Ovariectomized does were treated with progesterone. Blood progesterone level in the rabbits treated, twice daily, with 5mg progesterone after ovariectomy was similiar to that in the superovulated intact rabbits. Blood estradiol concentration of the rabbits after bilateral ovariectomy was beyond detection range. Blood progesterone concentration was significantly decreased to 7.6$pm$3.0ng/ml wi thin 3 hours after ovriectomy(p<0.05). However, that value was increased to 34.8$pm$8.2ng/ml by 5 mg progesterone treatment and this elevated level was significatnly decreased to 7.3$pm$2.4ng/ml at 12 hours after progesterone administration(p<0.05).