Over the past years, Ti microalloying technique has not been developed sufficiently compared to Nb and V, due to its special metallurgy characteristics. Higher chemical activity of Ti results in larger inclusions when Ti combines with O, N and S. In addition, higher temperature sensitivity of TiC precipitation leads to the instability of steel strips. Owning to the above reasons, the conventional high strength steels with the microstructure of martensite, bainite or the composite of the two were microalloyed with (0.01%~0.03%)Ti (mass fraction) for austenite grain refinement during soaking. The addition of high Ti (>0.1%) in microalloyed high strength martensitic or bainitic steels were rarely touched upon. The effects of tempering temperature on the microstructure and mechanical properties of high Ti microalloyed directly quenched high strength steel were investigated by TEM, SEM and physical-chemical phase analysis. The results show that with the increase of tempering temperature, the tensile curve has an obvious turning point. The tensile strength gradually decreases first and then increases, while the yield strength increases slowly. At tempering temperature 600 ℃, the experimental steel shows the best mechanical properties with tensile strength at 1043 MPa, yield strength at 1020 MPa and the elongation of 16%, while the Charpy impact energy is 67.7 J at -40 ℃. The main reason is that the amount of nanometer precipitates reaches the maximum, their distributions are also relatively uniform and the size is significantly small. The solid solution strengthening and precipitation strengthening increment of the experiment steel tempering at 600 ℃ were about 149.82 and 171.72 MPa, respectively.