Abstract: Objective 　To study the effect and mechanism of paclitaxel against human osteosarcoma . Methods 　The effects of paclitaxel on human osteosarcoma cell line MG-63, fresh osteosarcoma specimens and nude mice with osteosarcoma were assessed by MTT test, morphologic observation and flow cytometry (FCM) . Results 　The cytotoxity of paclitaxel against human osteosarcoma was in a time and dose-dependent manner. Paclitaxel induced apoptosis with bcl-2 phosphorylation, and this could be decreased by caspase inhibitors. Conclusion 　The cytotoxity of paclitaxel against human osteosarcoma maybe helpful to chemotherapy.