It is normal for children not to be able to crawl at the nine-month growth stage, and is related to how quickly the child develops. In the growth and development of children, the development of appropriate conditions to crawl from the lying position. 3-4 months can use the elbow to support the chest for a few minutes, 7-9 months with the hand or elbow to support the chest and abdomen in the same place, 8-9 months can be lying down from the sitting position chest and abdomen against the ground to crawl. At about 1 year of age, crawling is a “four-legged crawl” on hands and knees. Children who are nine months old and still can’t crawl may be due to slower development or behavioral habits and environmental influences. Observe the child for a longer period of time, provide positive encouragement, and increase the amount of instruction time from sitting to crawling. Parents can take relevant measures to promote the development of motor function, take the child interested in toys in front of the tease, so that the hands and feet on the ground to practice crawling, through repeated training can learn to crawl. In addition, the baby should be given vitamin D and calcium supplements in a timely manner. Parents are advised to encourage their children to move on their own with a positive attitude at this stage, and to go to the hospital for a detailed physical examination to determine whether there are any abnormalities in the development of bones and brain and nerves if necessary.