There are many reasons for the developmental delay of babies, which is mainly manifested in the motor development, physical development, language development and intellectual development lagging behind children of the same age. 1. Motor development: such as delayed movement, uncoordinated movement, inflexibility, lack of skill, etc., such as not being able to build blocks, not being able to run and jump well, and so on. 2. Physical development: if the height and weight are lower than that of children of the same age, this situation is related to the feeding difficulties and poor motor coordination of babies with developmental delay. 3. Language development: for example, babies can’t speak clearly, can’t finish a sentence completely, can’t learn to sing, and so on. 4. Intellectual development: such as stagnant expression, no smile on the face and other changes in expression, or giggling, drooling, no response to the call of others and other manifestations. When these situations occur, you need to be alert to the baby’s developmental delay, you need to go to the pediatrics or child health department in a timely manner, a clear diagnosis and treatment.