Abstract: Objective: To investigate the experience of body image change among the adolescents with osteosarcoma during treatment. Methods: Indepth interviews were conducted to 10 adolescents with osteosarcoma. The interview records were analysed with the Colaizzi phenomenological data analysis. Results: Three themes were extracted, negative perception (including feeling different, less attractive and conspicuous), passive assessment (including passive self-cognition, decrease of social desire and feeling isolated), and coping style (including maintaining normality and trying to accept). Conclusion: Changes in body image have side effects on the quality life in adolescents with osteosarcoma. Healthcare providers should guide patients to develop a comprehensive understanding of the changes in body images in order to improve their life quality.