为探索紧急避孕方法，对１３９名健康、月经规律的妇女在避孕失败或无保护的性生活后７２小时内就诊服药并随机分为３组：组Ⅰ（ｎ＝４６），首次口服米非司酮（息隐）２５ｍｇ，１２小时后重复１次，总量５０ｍｇ；组ⅡＩ（ｎ＝４６），首次服双炔失碳酯（Ｃ５３号）７．５ｍｇ，１２小时后重复１次，总量１５ｍｇ。组Ⅲ（ｎ＝４７），１次服息隐２５ｍｇ＋Ｃ５３号７．５ｍｇ。结果组Ⅰ、组Ⅲ无一例妊娠，避孕有效率１００％；组Ⅱ妊娠２例，接近预期妊娠数３．１６３，避孕有效率３６．７％。服药月经改变少，副反应发生率低。４５例在围排卵期同时作了激素测定及阴道超声波检查，激素变化可分为三种类型：无排卵型、排卵前后型与排卵后型。超声波所见与激素测定相符，显示米非司酮有较明显的抑制排卵或卵泡发育。结果表明，低剂量米非司酮单独服用５０ｍｇ或２５ｍｇ与双炔失碳酯７．５ｍｇ联合紧应用都可作为性生活后７２小时内的有效紧急避孕。 To explore the emergency contraception method, 139 healthy women with regular menstruation were treated within 72 hours after contraception failed or unprotected sex and randomly divided into three groups: group Ⅰ (n = 46), first oral mifepristone Ketone (interest hidden) 25mg, 12 hours after repeated 1, the total 50mg; group II (n = 46), the first service of an anordrin (C53) 7.5mg, 12 hours after the repeat 1 times the total 15mg. Group Ⅲ (n = 47), 1 service interest hidden 25mg + C53 7.5mg. Results In group Ⅰ and group Ⅲ, there was no pregnancy and the effective rate of contraception was 100%. In group Ⅱ, 2 cases of pregnancy were close to the expected number of 3.163 and the effective rate of contraception was 36.7%. Less medication menstruation, side effects of low incidence. 45 cases of ovulation during the period around the hormone determination and vaginal ultrasound examination, hormone changes can be divided into three types: anovulatory, anovulatory and anovulatory after ovulation. Ultrasound findings and hormones measured consistent, mifepristone showed more obvious inhibition of ovulation or follicular development. The results show that low doses of mifepristone alone taking 50mg or 25mg and an anordrin ester 7.5mg combined with tight can be used as an effective emergency contraception within 72 hours of sexual life.