骨盆的大小和形态是决定胎儿能否阴道分娩的重要因素之一，骨盆人口平面倾斜度（以下简称a）直接影响股先露的衔接。作者偶而发现临床所测的a并达不到经典著作中所说的60”土。故做此探讨。对象和方法对象：本组50例非孕汉族女性．年龄目25～30岁；本产24例．已产26例；身高150 The size and shape of the pelvis is one of the important factors that determine whether or not the fetus can be delivered vaginally. The inclination of the pelvic floor (hereinafter referred to as a) directly affects the connection of the first exposure. The authors occasionally found that the clinical test of a and can not reach the 60 "soil in the classic. Therefore, to do this study.Objects and methods of the object: the group of 50 non-pregnant Han women aged 25 to 30 years old; 24 cases. Has produced 26 cases; height 150