本文报道了国人9～13周龄43例胚胎外阴生殖器分化的情况与13周龄以上526例男性胎儿睾丸下降的解剖观察与统计。结果表明,外生殖器在9周前未辨认出性别,第10周时可辨认出男性,第12周男女性别区分明显。睾丸下降位置20周龄前全部平髂嵴,21周龄少数降至腹股沟腹环处,26～29周龄大部分在腹股沟管内,30～38周大部分入阴囊。 This article reports the anatomical observation and statistics of the genital differentiation of 43 cases of embryonic genitalia from 9 to 13 weeks of age in China and the descending testicular biopsy of 526 male fetuses aged 13 weeks and older. The results showed that genitals were not recognized by the genitalia 9 weeks ago, men were identifiable by week 10, and sex was clearly differentiated by week 12. Testicular descent position all 20 weeks before the iliac crest, 21-week-old few fell to the inguinal ring at 26 to 29 weeks of age most of the inguinal canal, most of 30 to 38 weeks into the scrotum.