Nine-month-old babies still can not crawl, you can see whether the baby can sit alone, such as can sit alone, can be temporarily observed to follow up the treatment, and regular outpatient follow-up growth and development of children’s health department. If the development is significantly behind the same age, usually with hypothyroidism, cerebral palsy and other factors, can be under the guidance of the doctor for targeted treatment and training. 1. Physiological factors: It is normal for some babies to be unable to crawl at nine months of age, probably due to less training and individual differences in babies. It is recommended to increase the appropriate amount of activity every day, and relevant training, but each training should pay attention to the cycle of gradual, do not let the body tired. 2. Hypothyroidism: babies with hypothyroidism may have backward growth and development. If hypothyroidism is considered as a possible cause, relevant examinations such as complete set of thyroid function can be perfected and levothyroxine sodium tablets can be used as replacement therapy under the guidance of the doctor. 3. Cerebral palsy: known as cerebral palsy, due to various reasons of brain function damage, may affect the motor nerves, resulting in nine-month-old babies can not crawl normally, and even can not sit alone. It is recommended that under the guidance of a professional doctor to be rehabilitation therapy, functional training, to help the baby to restore physical activity. There are many factors that may cause nine-month-old babies to be unable to crawl. Parents are advised to visit the pediatric outpatient clinic regularly and follow the doctor’s instructions for targeted treatment.