N-ras is one of the transforming genes in human hepatic cancer cells. It has been found that N-ras was overexpressed at the mRNA and protein level in hepatoma cells. In order to explore the biological roles of N-ras in human hepatic carcinogenesis and the potential application in control of cancer cell growth, a pseudotype retrovirus containing antisense sequence of human N-ras was constructed and packaged. A recombinant retrovirus vector containing antisense or sense sequences of N-ras cDNA was constructed by pZIP-NeoSV (Ⅹ) 1. The pseudotype virus was packaged and rescued by transfection and infection in PA_(317) and ψ2 helper cells, It has been demonstrated that the pseudotype retrovirus containing antisense N-ras sequence did inhibit the growth of human PLC/PRF/5 hepatoma cells aceompanied with inhibition of p21 expression, while the retrovirus containing sense sequence had none. The pseudotype virus had no effect on human diploid fibroblasts. It has been found that N-ras was overexpressed at the mRNA and protein level in hepatoma cells. In order to explore the biological roles of N-ras in human hepatic carcinogenesis and the potential application in control of cancer cell growth, a pseudotype retrovirus containing antisense sequence of human N-ras was constructed and packaged. A recombinant retrovirus vector containing antisense or sense sequences of N-ras cDNA was constructed by pZIP-NeoSV (Ⅹ) 1. The pseudotype virus was packaged and rescued by transfection and infection in PA_ (317) and ψ2 helper cells, It has been demonstrated that the pseudotype retrovirus containing antisense N-ras sequence did inhibit the growth of human PLC / PRF / 5 hepatoma cells aceompanied with inhibition of p21 expression, while the retrovirus containing sense sequence had none. The pseudotype virus had no effect on human diploid fibroblasts.