Abstract: By means of scanning electron microscopy, X-ray diffraction, transmission electron microscopy and tensile tester, the microstructure and mechanical properties of hot rolled transformation-induced plasticity (TRIP) steels which were prepared through relaxation-precipitation-phase transformation technology were investigated. The results show that a accurate setting proportion of ferrite could be obtained by controlling the holding time during relaxation after rolled. It was also found that tensile strength did not decline as a result of stronger TRIP effect in the case of larger amount of ferrite and less bainite. Because of more residual austenite and high mechanical stability of the residual austenite, strength and ductility were well matched in hot-rolled TRIP steels.