Abstract: In the field of structural strengthening, applying prestress to strengthening materials could be effective in constraining crack development, improving the utilization of materials, diminishing or eliminating leg-stress effect and enhancing the strengthening effect. Active constraint by prestress technology can significantly improve the mechanical and deformation properties of reinforcement concrete(RC) columns. In this paper, recent developments in the field of RC column strengthening using active constraint were briefly reviewed. Particular emphasis is taken to the new retrofit technique of RC column using prestressed steel jacket(PSJ), developed and realized in the structural laboratory in Huaqiao University. The researches, such as the aseismic performance, shear performance and axial compression performance of retrofitted RC columns using PSJ, were introduced. The results show that PSJ can effectively improve the aseismic performance, and enhance the shear strength, axial bearing capacity and deformation property. The prestress of steel jacket can be applied easily and controlled precisely. After strengthened, the section size and the original stiffness of components are not changed, which will not influence the aseismic shear distribution of an original structure. These results are encouraging, and the retrofit technique could be broadly applied in the field of structural strengthening. Finally, the outlook and suggestion about the PSJ retrofit technology were proposed.