There is no clear stipulation on how old the baby can sleep on a pillow, at present, it is recommended that babies start to sleep on a slightly thicker pillow after three months. Infants within three months of the spine is straight, there is no adult spine unique physiological curvature, such as neck curvature forward, thoracic spine backward, lumbar spine forward and other physiological curvature, lying back and back of the brain naturally at the same level, to ensure that the back of the neck muscles naturally relax, to help its growth and development, at this time it is not recommended that infants sleep on pillows. Infants three months after the neck, spine section will be forward, the formation of physiological curvature, torso growth accelerated, shoulder slightly wider, three months after the baby can use a slightly thicker pillow, can make the spine physiological curvature and position more comfortable. But pay attention to the height of the pillow, too high a pillow, easy to cause the neck to bend, may cause breathing difficulties, affecting growth and development and so on.