The common reasons for the formation of mother’s buttocks are mainly as follows: 1. It may be caused by excess nutrition. The traditional concept of the Chinese people is that after childbirth, a large supplement is needed to increase the secretion of breast milk and to promote the recovery of the mother; however, this concept only targets the situation of people’s general malnutrition in traditional societies. The supplementation of essential nutrients is enough, excessive supplementation such as drinking a lot of pig’s feet soup or other high-energy food will cause a lot of fat deposition throughout the body, and the buttocks which is a very common part of fat deposition. 2, may be caused by sitting or standing for a long time after childbirth, Chinese people often have the habit of sitting on the moon, in the process of sitting or standing for a long time after childbirth will slow down the blood circulation in the buttocks, and then produce edema here. 3. It may also be caused by the instability of the pelvic joints, for example, excessive force during labor may cause the separation of the pubic symphysis, and in serious cases, it may even affect the sacroiliac joints after delivery, and the instability of the joints may cause changes in the shape of the hips.