Abstract: The effects of soaking temperature and soaking time on microstructure and mechanical properties of the MS1470 martensitic steel were investigated by using optical microscopy,scanning electron microscopy,transmission electron microscopy and tensile testing machine.The results show that with the increasing of soaking temperature from 740℃ to 820℃ and both the tensile strength and yield strength of the MS1470 steel increased the prolongation of soaking time from 0 s to 180 s,the percentage elongation after fracture decreased.The microstructure of MS1470 steel was composed of ferrite and large amount of martensite.With increasing soaking temperature and prolongation soaking time,the volume fraction of martensite increased and the size of the microstructure decreased.