Infants 3 months physical examination check height and weight, head circumference, vision and hearing, vitamin D level, developmental intelligence evaluation, blood routine and so on. 1. Height and weight: Infants should go for height and weight measurement at the age of 3 months, which is an important indicator for evaluating growth and development. Height growth in the first three months is about 11-13cm, and weight growth should be about double that of the newborn. 2. Head circumference: 3-month-old babies should be measured during the physical examination of the head circumference, the measurement of the head circumference can reflect the development of the baby’s brain and skull, which can reflect the size of the brain capacity, the head circumference should be increased by about 6cm in 3 months. 3. Vision and hearing: Infants should have their vision and eyesight checked at 3 months of age to determine whether the baby has abnormal hearing and abnormal vision. 4. Vitamin D level: infants 3 months to check the vitamin D level, serum calcium, iron, zinc, inorganic phosphorus, etc., there are abnormalities can be under the guidance of the doctor appropriate supplementation of vitamin D or minerals. 5. Developmental Intelligence Evaluation: Infants 3 months to test the baby’s neurobehavioral awareness through some basic fine motor, such as autonomy to lift the head, grasping awareness, to determine the baby’s gross motor and intellectual development. 6. blood routine: blood sampling and checking blood routine can understand whether 3-month-old infants have anemia, thrombocytopenia and other conditions. Infants 3 months can go to the regular hospital physical examination, there are abnormalities should be dealt with promptly.