The common causes of children’s leg pain are growing bone pain, hip dislocation, osteosarcoma and so on. 1. Growing bone pain: common in children aged 2~7, mainly due to rapid growth of bones and local nerves, muscles, tendons and other growth and developmental disorders, thus causing leg pain, the pain is more pronounced at night, usually not accompanied by other traumas, usually do not need special treatment, with the growth of age, often can be relieved on their own. 2. Hip dislocation: the cause of children’s leg pain is also hip dislocation, because dislocation can lead to poor joint alignment and incorrect body force line, thus causing leg joint pain. 3. Osteosarcoma: if the child’s leg has osteosarcoma, because the tumor tissue destroys the bone cortex and stimulates the periosteal nerve endings in the leg, it will also cause leg pain, and with the development of the disease, it will also appear limp, weight loss and other symptoms. Children always say leg pain may also have other reasons, such as trauma caused by incomplete fracture, infection caused by osteomyelitis, etc., it is recommended to go to the hospital in time, after clarifying the cause of the disease for targeted treatment, so as not to delay the condition.