OBJECTIVE; To review the molecule mechanism of multidrug resistant osteosarcoma cell apoptosis induced by laser. DATA SOURCES; An online search of Pubmed database and CNKI database was undertaken to identify the articles published from 1996 to 2006 by using the keywords of “laser, osteosarcoma and apoptosis”, and language was limited to both Chinese and English. STUDY SELECTION; The articles were primarily screened and then the full-texts were searched. Included criteria: relevant to the mechanism of tumor cell apoptosis induced by laser. Articles were excluded because of repetition and obsolescence. DATA EXTRACTION; Totally 74 articles were found and 31 of them were selected according to the inclusive criteria as described above. Of the 31 articles, 5 articles were related to reactive oxygen species, 5 were associated with intracellular calcium concentration, 6 were involved in protein kinase C and 5 in Bcl-2 respectively. The last 8 were about P53 in the tumor apoptosis induced by laser. DATA SYNTHESIS; The mechanisms that laser induces osteosarcoma cell apoptosis include mainly reactive oxygen species, intracellular calcium concentration, protein kinase C, Bcl-2, p 53 and so on. The recent reports focus on the proliferation improvement of low-intensity laser on normal cells, but few reviews the biologic effect of tumor cells, especially multidrug resistant osteosarcoma and animal models. It is presumed to be correlated with the mechanism involved above. CONCLUSION; The mechanism that laser induces osteosarcoma cell apoptosis is still unclear, and is mainly related to reactive oxygen species, intracellular calcium concentration, protein kinase C, bcl-2, p 53 and so on.