Early symptoms of osteosarcoma are mainly manifested as lump, joint pain, numbness of limbs and fracture. 1. Lump: many patients with bone cancer will have a hard lump on the surface of bone at the early stage of development, some of them are accompanied by pain, some of them are painless. 2. Joint pain: joint pain may appear in the early stage of the disease, which may be dull pain, stabbing pain, pulling pain and so on. 3. Numbness of limbs: when the tumor tissue compresses the nerves, it may affect the local blood circulation and lead to numbness of limbs. 4. Fracture: some patients may have one or more fractures without obvious causes. Once the above symptoms appear, go to the orthopedic department of the hospital as soon as possible to improve the relevant imaging and laboratory examination, to clarify the severity of the disease and make timely intervention.