Abstract: Objective To study the correlation between Ki-67 and Bcl-2 expression in osteosarcoma and its chemotherapeutic effect. Methods EnVision immunohistochemistry was used to detect Ki-67 and Bcl-2 expression in 25 osteosarcoma patients admitted to our department in September 2005-December 2006 before chemotherapy. Tumor necrosis rate in these patients was assayed after three courses of large dosage chemotherapy. Results The expression rate of Ki-67 and Bcl-2 in osteosarcoma was 48% and 44%, respectively. No difference was found between Ki-67 and Bcl-2 expression in osteosarcoma and tumor necrosis rate（P＞0.05）. Ki-67 and Bcl-2 expression in osteosarcoma were correlated（r=0.605 6, P＜0.01）. Conclusion Ki-67 and Bcl-2 expression in osteosarcoma cannot be used as an index of the chemotherapeutic effect on osteosarcoma although they were correlated.