Aging strengthening and mechanical properties of P and Ti microalloyed high strength steel was investigated. It was shown that there is a significant effect of aging strengthening in the steel. Based on the aging strength and work hardening, the strength level of 1200 MPa and the elongation over 10% can be obtained. The combination of strength and elongation can be adjusted by the process parameters. The characteristics, microstructure and mechanical properties of this steel were discussed.