Abstract: <b<Objctive</b< To study the change of malignant bone tumor after chemotherapy. <b<Methods</b< imaging Comparision must be based on x-radiograph, CT scan and MRI, Volute sample 31 patients diagnosed malignant bone tumor, of which osteosarcoma 15,Ewihgs Sarcoma 4,SonoviSarcoma 4,and cellulsarcoma 8,grouped according to histology character and Sensitivity to antitumor drugs. <b<Results</b< After chemotherapy, clinical pain was reduced and the volume was shrinked. The surrounding of pathology in imaging changed from blur to distinct, osteosclerosis and encircling bone increased, the new blood vessel in trusting tumor reduced.14 changed greatly, the total efficient rate was 45%,9 changed avergely,8 changed little. <b<Conclusions</b< From this research we can conclude that the death rate of tumor cell was 90%,the survived rate of 5 years was 80-90%.Comprehensive chemotherapy to the patients may be effective or not, but it needs a long observe course. The curative effect 12 osteosarcoma, Ewings sarcoma, sonival-sarcoma was higher, there was no obvious change in cell ulsarcome and a few tumor with large volume.