Abstract: Objective: To analyze the clinical factors that separate low- and high-risk osteosarcoma after neoadjuvant chemotherapy. Methods:Many indices, including clinical manifestation, hematological examination and X-ray changes, from 55patients with osteosarcoma who were treated with neoadjuvant chemotherapy in the study department from De -cember 1999to December 2006were reviewed. During follow-up, the patients were classified as having high-risk osteosar -coma if recurrence, metastasis or death occurred. If these events did not occur, the patients were classified as having low-risk osteosarcoma. Several indicators including general materials , tumor volume, X-ray type, X-ray scoring, AKP and LDH were recorded and analyzed with various statistical methods to study the difference between the high-risk and low-risk groups. Results: Fifty-five patients with osteosarcoma were followed up for 3 to 10years. Of these, 25patients developed recurrence or metastasis or died, and were classified as being in the high-risk group ( 45%), and30patients with no recur -rence or metastasis were classified as being in the low-risk group ( 55%). The results of multivariate analysis showed there were no differences between the high-risk and low-risk groups in many regards, except for pre-chemotherapy tumor vol-ume, pre-chemotherapy AKP and pre-chemotherapy LDH. Conclusion:A patient should be considered to have high risk os -teosarcoma when pre-chemotherapy AKP ≥250 IU/L, pre-chemotherapy LDH ≥240 IU/L, and pre-chemotherapy tumor volume ≥150 cm3.