Abstract: ［Abstract］Objective　To investigate the influencing factors of prognosis of osteosarcoma in children and adolescence．Methods　We retrospectively analyzed the clinical data of 32 adolescent patients with osteosarcoma admitted in our hospital from January 1990 to January 2006．All adolescent patients with osteosarcoma were given COSS 96 treatment protocol．The 5 a overall survival（OS）rate and event-free survival（EFS）rate were analyzed and their relation with metastasis，surgery types，the location of osteosarcoma，histological types，reactions to preoperative chemotherapy，gender and age of patients，were also analyzed．Results　The 5 a OS and EFS was 59.4%（19/32）and 46.9%（15/32），respectively．The 5 a OS of patients without metastasis was significantly higher than that of patients with metastasis（P＜0.05），and was significantly higher in patients with late metastasis than early metastasis（P＜0.05）．There was no significant difference in the recurrence rate，5 a OS and 5 a EFS between Limb salvage surgery and amputation surgery（P＞0.05）．There was also no significant difference in 5 a OS and 5 a EFS between different location of osteosarcoma and different histological types（P＞0.05）．The 5 a OS and 5 a EFS of patients sensitive to new chemotherapy were significantly higher than those of patients insensitive to new chemotherapy（P＜0.05）．There was no significant difference in 5 a OS and 5 a EFS between patients with different gender（P＞0.05）．The 5 a OS and EFS of patients younger than 14 were significantly higher than those of patients over 14［75%（12/16）and 68.8%（11/16）vs. 43.8%（7/16）and 26.7%（4/16），P＜0.05］．Conclusions　 Most adolescent patients with osteosarcoma can get satisfying therapeutic effect by enhanced chemotherapy and surgery．Limb salvage surgery can improve the life quality of patients，while does not increase the risk of poor prognosis．The prognosis is poor in patients with metastasis and local recurrence， while the prognosis is good in patients with good reaction to chemotherapy and younger than 14 years