Abstract: Initial research on phase maldistribution of gas-liquid two-phase flow at a T-junction is reviewed. With further research on such maldistribution，the T-junction acting as phase separator of two-phase flows has gradually caught attention of petrochemical and chemical industries. Geometry structure and characteristic features of the T-junction for two-phase flows are introduced. Research progress of gas-liquid and liquid-liquid two-phase flows at the T-junctions is reviewed and research on gas-solid and liquid-solid flows at the T-junctions is briefly summarized. Finally，the research area for further study is presented.