Chalcone reductase( CHR) is a key enzyme in the biological synthesis of daidzein,which is the main composition of isoflavones. In this study,chalcone reductase gene Gmchr4( Gen Bank code: KF938604) was isolated from the soybean Jinong 17. This gene consisted of a 1 410 bp fragment including an open reading frame of 969 bp. Phylogenetic tree of CHR protein was performed by using MEGA4. 0 program. The Gmchr4 gene was transformed into tobacco,and the presence of isoliquiritigenin in tobacco was confirmed by high- performance liquid chromatography( HPLC). Expression of Gmchr4 gene under the control of 35 S CaMV promoter was also examined by real- time fluorescence quantitative PCR( Q- PCR). Cloning and characterization of Gmchr4 gene were beneficial to elucidate the biological synthesis and regulation of soybean isoflavones,and to manipulate the phenylpropanoid pathway generating isoflavonoid phytoalexin.