The severe acute respiratory syndrome (SARS) has been one of the most epidemic diseases threatening human health all over the world. Based on clinical studies, SARS‐CoV (the SARS‐associated coronavirus), a novel coronavirus, is reported as the pathogen responsible for the disease. To date, no effective and specific therapeutic method can be used to treat patients suffering from SARS‐CoV infection. RNA interference (RNAi) is a process by which the introduced small interfering RNA (siRNA) could cause the degradation of mRNA with identical sequence specificity. The RNAi methodology has been used as a tool to silence genes in cultured cells and in animals. Recently, this technique was employed in anti‐virus infections in human immunodeficiency virus and hepatitis C/B virus. In this study, RNAi technology has been applied to explore the possibility for prevention of SARS‐CoV infection. We constructed specific siRNAs targeting the S gene in SARS‐CoV. We demonstrated that the siRNAs could effectively and specifically inhibit gene expression of Spike protein in SARS‐CoV‐infected cells. Our study provided evidence that RNAi could be a tool for inhibition of SARS‐CoV.