Four-month male baby length 57.9~71.7cm, weight 5.25~10.39kg; female baby length 56.7~70.0cm, weight 4.93~9.66kg. According to the norms of children’s growth and development evaluation, the newborn height and weight norms are 45.2~55.8cm in length and 2.26~4.66kg in weight for male babies; 44.7~55.0cm in length and 2.26~4.65kg in weight for female babies, while the length of four-month-old male babies ranges from 57.9~71.7cm in length and 5.25~10.39kg in weight for female babies; and the length of four-month-old female babies ranges from 56.7~70.0cm in length and 5.25~10.39kg in weight for female babies. length 56.7~70.0cm and weight 4.93~9.66kg. The height and weight standards of four-month-old babies are also very much related to their height and weight at birth. If the child’s weight and height are on the small side at birth, his or her height and weight may also be on the small side at four months. If the child’s weight is on the small side, it is important to observe if there is a problem of insufficient breastfeeding or improper formula feeding. If the height and weight are significantly different from the standard, the child should be taken to the hospital in time for the relevant examination.