The changes in serum specific hCG and prolactin levels were studied in 20 women after the evacuation of normal pregnancy at 5-10 weeks (group A) and 10 patients after the evacuation of molar pregnancy of 9-16 weeks (group B). The elimination of circulating hCG was faster in group A than in group B, and that in women after term delivery(group C)was faster than in both groups A and B. The half-life of the serum hCG level was 44.4 hrs in group A, 42.7hrs in group B, and 38.9hrs in group C, respectively. The mean level of serum prolactin in group A was 27.4ng/ml at 0 day, 64.5ng/ml at 4-7 days, and 31.9ng/ml at 13-15 days after evacuation, respectively. The surge was statistically significant. Though no regular tendency was found in the prolactin levels in group B, the levels were relatively higher than in group A and nonpregnant women. No correlation was found between hCG and prolactin levels in either group A or group B. The administration of drugs, such as methotrexate, did not affect the prolactin levels. On BBT, the resumption of ovulation tended to occur when the prolactin level, rather than the hCG level, returned to its normal range.