Based on the principle of the integrated strengthening of steel, the strengthening and the softening of HSLC steel have been studied by controlling the precipitation of carbon in steel around A1 temperature. The results show that strength of HSLC steel produced by TSCR can be further increased. By using temper-slow cooling, σ_s of HSLC steel(ZJ330) produced by TSCR can be decreased from 344 MPa to 225 MPa to meet the requirement of producing basal plate for cold rolling. Problems about ferrite rolling, ultra fine grain steel and a possible new type building materials have been discussed.