Three-month-old babies need attention in terms of feeding, vaccinations, etc., and they also need to be careful not to engage in behaviors such as overfeeding or cutting the umbilical cord. Three-month-old babies are encouraged to breastfeed, so it is important to breastfeed on demand, and if the baby is formula-fed, the amount of milk should be 720-900mL per day, six times a day, with an interval of 3-4 hours between feedings. At the same time baby feeding to pay attention to the child’s weight as well as length development. Three-month-old babies should be vaccinated, half an hour after the polio vaccination and two hours before the vaccination should not eat milk, otherwise it will cause failure. After vaccination, pay attention to the child’s mental condition, as well as possible fever, diarrhea and other symptoms. In addition, be careful not to feed your baby too much milk, which is likely to cause accumulation of food or diarrhea. At the same time, pay attention to the care of the baby’s umbilical cord, do not use water to clean, and wait for it to fall off naturally. Otherwise, it is likely to cause inflammation of the umbilical cord, leading to the baby’s umbilical infection problem.