To survey the age and gender characteristics of motor function including motor milestone, primitive reflexes, postural reaction, and muscle stone in infants and to evaluate the reliability of items of motor function. 【目的】观察城乡3、6、9、12个月婴儿运动里程碑、原始反射、姿势反应和肌张力发育的年龄和性别特征,评价检查项目信度。