目的　探讨不同剂量米非司酮配伍米索前列醇用于黄体晚期生育调节的有效性、安全性和可接受性。方法　预期月经来潮前 3d分别口服米非司酮 5 0mg(A组 )、75mg(B组 )、10 0mg(C组 ) ,顿服 ,并于4 8h后均加服米索前列醇 4 0 0 μg。 结果　共接纳 2 4 6名受试者 ,服药周期 86 8个 ,共有 32次继续妊娠 ,总妊娠率 3.6 8% ,其中A、B、C 3组妊娠率分别为 7.95 % ,2 .10 % ,1.5 7% ,终止妊娠有效率分别为 6 8.1% ,91.9% ,92 .9%。所有受试者的月经周期和月经量均无明显影响。结论　预期月经来潮前 3天左右服用小剂量米非司酮配伍米索前列醇进行生育调节均能有效达到避孕目的 ,尤以 75mg米非司酮具有剂量小、效果好、副作用小的优点 Objective To investigate the efficacy, safety and acceptability of different doses of mifepristone combined with misoprostol in the regulation of late luteal growth. METHODS: Mifepristone 50 mg (group A), 75 mg (group B), and 100 mg (group C) were pretreated with mifepristone three days before menstrual cramps. After 48 hours, patients were given misoprostol 400 μg. Results A total of 246 subjects were enrolled in this study. The duration of medication was 86.8. There were 32 consecutive pregnancies with a total pregnancy rate of 3.6%. The pregnancy rates in groups A, B and C were 7.95%, 2.10% 1.5 7%, the effective rate of termination of pregnancy were 6 8.1%, 91.9%, 92.9%. All subjects had no significant effect on menstrual cycle and menstrual flow. Conclusions It is expected that taking a small dose of mifepristone and misoprostol for birth control around 3 days before menstruation will be effective in contraception, especially for mifepristone 75mg, which has the advantages of small dosage, good effect and small side effects