【Objective】To retrospectively analysize the clinical effect of neoadjuvant chemotherapy for 18 children with osteosarcoma.【Methods】Eighteen children with osteosarcoma were classified into type ⅡB by Enneking Surgical Classification.All patients were treated by neoadjuvant chemotherapy regimen that was preoperative chemotherapy、operation and postoperative chemotherapy.At first period,all patients accepted huge-dose MIX regimen(MTX 200 mg/kg or 12 g/m2).At second period,they accepted IFO regimen(2 g/m2) continuously for 5 days.At third Period,they accepted AP regimen(ADM 60mg/m2 and DDP 120 mg/m2).Every period had 12 interval days.Three periods were used as a treatment course.All patients were treated by two chemotherapy courses before operation.After two weeks,they accepted operation and then they were treated by two or three chemotherapy courses after operation.【Results】All patients accepted histological evaluation after operation.Two groups were classified by response.Fourteen patients significantly responsed to chemotherapy,rated 77.8% in all patients.Four patients mildly responsed to chemotherapy rated 22.2%.One-year survival rate of two groups was 92.8%、50%,respectively.Two-year survival rate of two groups was 71.4% 、25%,respectively.【Conclusions】Neoadjuvant chemotherapy has a role in complex therapy for children osteosarcomas.The evaluation by histological method is an important index that would help us to judge prognosis.