Abstract: The effects of intercritical annealing temperature on the microstructure evolution and mechanical properties of Fe-0.27C-3.84Mn-1.6Al-0.6Si-0.07V-0.03Nb（4%Mn） medium-Mn steel were explored. The result shows that when the intercritical annealing temperature increases from 700 ℃ to 740 ℃, the volume fraction of retained austenite is increased, while the mechanical stability is decreased. After intercritical annealing at 730 ℃ for 20 min, the microstructure of the specimen consists of lath/globular ferrite and lath/globular retained austenite, and the volume fraction of retained austenite is 47.7% with suitable mechanical stability. Consequently, persiand sufficient TRIP effects can occur during deformation, the excellent mechanical properties are obtained, the yield strength is 848 MPa, the tensile strength is 1118 MPa, the total elongation is 42.1% and the product of tensile strength and elongation (PSE) reaches 47.1 GPa·%.