共征集２４名停经≤４９ｄ、要求中止妊娠的健康妇女，分４组，各组依次口服米非司酮５０ｍｇ（组Ⅰ）、５０ｍｇＱ１２ｈ×６（组Ⅱ）、２００ｍｇ（组Ⅲ）和６００ｍｇ（组Ⅳ），首次服药后７２ｈ行人流术（组Ⅰ）或阴道内放置卡前列甲酯栓（ＰＧ０５）１ｍｇ（组Ⅱ～Ⅳ）。结果显示各组之间临床效果及临床经过差异均无统计学意义（Ｐ＞０．０５）。血清β－ｈＣＧ、Ｅ２Ｐ变化趋势亦基本一致。β－ｈＣＧ在用药前２４ｈ内上升５０％～１００％（Ｐ＜０．０１），服药后至孕囊排出前仍呈上升趋势，口服首剂米非司酮后，各组Ｅ２水平亦持续高于服药前，而Ｐ水平则缓慢下降。妊娠中止后，上述三种激素急剧下降。服药期间，各组ＰＲＬ和皮质醇明显上升，孕囊排出后前者下降缓慢，而后者下降迅速，ＡＣＴＨ、Ｔ３、Ｔ４和ＴＳＨ变化均无统计学意义。本研究结果表明来非司酮（５０ｍｇＱ１２ｈ×６，２００ｍｇ和６００ｍｇ）抗早孕时无明显量效关系；其主要作用部位似不在卵巢和绒毛；但对垂体一肾上腺轴有一定影响，尤其是大剂量时；对垂体一甲状腺轴影响不明显；ＰＲＬ水平变化似为药物直接作用所致，其临床意义尚待进一步研究。 A total of 24 healthy women with menopause ≤ 49 days were enrolled and divided into 4 groups. Each group was given oral mifepristone 50mg (group Ⅰ), 50mgQ12h × 6 (group Ⅱ), 200mg (group Ⅲ) and 600mg Ⅳ). After 72 hours of the first dose, pepstration (group Ⅰ) or vaginal instillation of 1 mg of PG05 (group Ⅱ ~ Ⅳ) was administered. The results showed no significant difference in clinical effect and clinical difference between the groups (P> 0.05). Serum β-hCG, E2P trend is basically the same. β-hCG increased by 50% -100% within 24h before treatment (P <0.01), and it showed an upward trend before taking the medicine to the gestational sac. After oral administration of the first dose of mifepristone, the levels of E2 in each group continued to increase Before taking medicine, P level decreased slowly. After the termination of pregnancy, the three hormones dropped sharply. During the medication, PRL and cortisol increased significantly in each group, while the former decreased slowly after excretion of gestational sac, while the latter decreased rapidly. There was no significant difference in ACTH, T3, T4 and TSH. The results of this study showed that there was no significant dose-response relationship between nifepristone (50mgQ12h × 6,200mg and 600mg) in anti-early pregnancy. The main site of action was not ovarian and villous, but had some effect on pituitary-adrenal axis, especially high dose ; On the pituitary-thyroid axis is not obvious; PRL level changes as a direct result of the drug, its clinical significance remains to be further studied.