Objective:Survivin is one of the apoptosis inhibitor genes and is rarely expressed in adult tissues. However, survivin expression has been detected in various human cancers and correlations have been recognized between the level of expression of this gene in tumors and prognosis. In this study, we investigated the effect of Survivin-siRNA on the drug sensitivity of osteosarcoma cell line MG-63. Methods:Two siRNAs (Survivin-siRNA1, Survivin-siRNA2) specifically targeting Survivin gene were chemically synthesized and transfected into MG-63 cells. The Survivin mRNA level was detected by reverse transcription-polymerase chain reaction (RT-PCR). The survivin protein expression and cell apoptosis rate were analyzed by flow cytometry (FCM). The 50% inhibition concentration (IC50) of cisplatin (DDP) and adriamycin (ADM) on MG-63 cells was determined by MTT method. Results:Two short siRNA targeting survivin down-regulated the transcription of survivin gene dramatically and elevated apoptosis rate. They increased the drug sensitivity of MG-63 cells to ADM by five-fold and to DDP by nine-fold. Conclusion:Validated Survivin specific siRNA can effectively inhibit Survivin expression in survivin-overexpressing osteosarcoma MG-63 cell line and enhance the drug sensitivity of MG-63 cell line to ADM and DDP. Short survivin-siRNA mediated gene silencing may be a useful therapeutic strategy for osteosarcoma. These results suggest that survivin might be helpful for diagnosis of osteosarcoma and survivin siRNA combined with adriamycin or cisplatin may be a feasible strategy to enhance the effects of chemotherapy in patients with osteosarcoma.