Objective:To study the inhibition of survivin expression by small interference RNA(siRNA) synthesized in vitro in renal cancer cell line 786-O. Methods:Three groups of survivin siRNAs were chemically synthesized in vitro and then transfected into cell line 786-O. The expression of survivin mRNA and protein after transfection were detected by reverse transcription polymerase chain reaction(RT-PCR)and Western Blotting. The proliferation of cells was detected by MTT. Results:Two sequence specific siRNAs targeting survivin down-regulated the expression of survivn mRNA and protein. The proliferation of cells was inhibited after transfection. The third one was ineffective. Conclusion:Sequence specific siRNA targeting survivin can efficiently inhibit the survivin expression and cell proliferation in renal cancer cell line 786-O. The successful application of RNAi targeting survivin might extend the list of available gene therapeutic modalities in renal cancer.