Infants with developmental delay: 1. newborns or infants within 3 months of age are easily frightened and cry more than once; 2. infants have sharp and piercing cries, sometimes screaming, with no change in pitch; 3. aversion to breast milk and sleep difficulties, early feeding difficulties, symptoms such as drooling, easy to be frightened by noise, enhanced embrace reflex or with crying; 4. 4-6 weeks after birth still can not tease, do not recognize people, slow to respond, unstable head lifting at 3 months of age 4, the hand can not make a fist, 4 months still thumb inward, the hand can not open, 4-5 months when the waist can not swing the head uncertain, 5 months after seeing objects will not reach out to grasp objects; 5, not able to do normal infant movement, such as low muscle strength can not roll over, slow movement, stiff, do not like bathing, love to jerk, bilateral limb movement asymmetry; 6, roll over is reflexive, not stage roll over, poor crawling awareness, no hand support crawl, no separation action, more sleep, purposeless hyperactivity, inattentive, short time to eyes, etc.