Abstract: The effect of deformation in austenite region and tempering temperature on microstructure and mechanical properties of SPV490 steel was studied.In direct quenching and tempering process,strength of samples was remarkably increased when adopting control rolling in austenite recrystallized zone,while impact toughness was decreased.With 44% deformation in recrystallized zone for two-phase rolling,because fine microstructure transformed from austenite with deformed band and high dislocation density was achieved,samples had good mechanical properties.