Baelantang(BLT) is used in female infertility caused by ovulation disorder. An attempt was to evaluate the influences of BLT on the serum concentrations of FSH, LH, estradiol(E2) and progesterone, the histological and optical changes of ovary, ovary weight of rats. The results of the study were as follows : 1. Blood FSH level increased experimental group as compared with control group on 7th day, which showed no efficacy. 2. Blood LH level increased in experimental group as compared with control group on 7th day and decreased 14th day, which showed no efficacy. 3. Blood E2 level decreased in experimental group as compared with control group on 7th day and increased 14th day, which showed no efficacy. 4. Blood progesterone level increased in experimental group as compared with control group on 7th day and decreased 14th day, which showed no efficacy. 5. In histological observations of ovary, ovulation increased in experimental group as compared control group on 7th day and on 14th day, which showed no efficacy. 6. In optically observations of ovary, weight of ovary increased in experimental group as compared with control group on 7th day and 14th day, which showed no efficacy. According to these results, BLT did not influence on the ovulation and ovary of rats.