If breast milk is sufficient, try to feed exclusively with breast milk, and if breast milk is insufficient, you can choose formula feeding. Basically, it is not recommended to add complementary foods to a three-month-old child. After four months, you can consider using some complementary feeding, for example, you can add some rice flour, vegetables and fruits into puree for your baby, but pay attention to the amount, if you add a lot at once, your baby may have indigestion. From the beginning of a small amount slowly become more, from a single gradually increase the variety.