Abstract: Many experimental methods such as electron microscopy and chemical phase analysis were used to study the precipitates of high-strength weather-resisting steel with titanium addition, and the precipitation process was analyzed based on thermodynamics calculations. The results showed that the main particles in the steel were TiC, TiCN, Ti₄C₂S₂ and TiN, and almost TiN particles have precipitated before hot rolling. A large number of nanometer TiC particles distributed on dislocations in ferrite. The size distri- bution of MC phase changed with increasing titanium content. The obvious increase in volume fraction of small scale particles heightened the yield strength of the steel through precipitation strengthening.