Normal children’s growth and development has a certain regularity, with the age of: 3 months the baby will raise his head; 4 months will recognize the mother, and can take the initiative to grasp the object, make a laugh; 6 months will sit; 8 months will crawl, and can call mom and dad; 1 year old will walk and talk. The head circumference of a newborn baby is about 34cm at birth, and reaches about 40cm at 3 months, 46cm at 1 year, 48cm at 2 years, and 50cm at 5 years; the weight is about 3kg at birth, twice as much at 3 months, 3 times as much at 1 year, 4 times as much at 2 years, and 2 times as much after 2 years; the height of a baby at birth is the weight of his/her age times 2 plus 8kg. The height of a baby is about 50cm at birth, 62.5cm at 3 months, 75cm at 1 year, 87cm at 2 years, and 75cm after 2 years of age multiplied by 7. Parents can use these criteria to determine if their child’s growth is normal.