Abstract: To develop Q960 steel plates used for engineering machinery, heat treatment technologyies of quenching and tempering was studies. The results show that the optimum quenching technology was heating at 900 ℃ for 20 min, and the optimum tempering technology was heating at 600 ℃ for 40 min. The microstructure of tested steel was temper sorbit after optimum quenching and tempering heat treatment, and yield strength, tensile strength, elongation and impact energy at -40 ℃ respectively was 1 030 MPa, 16.8% and 144 J, they could meet the acquirement of GB/T 16270-2009.