In this paper, a new type steel plate with nano-layered martensite lath structure was produced by heavy cold-rolling. After rolling, subsequent annealing has great effect on the deformed martensite morphology and grain refinement. Microstructure recrystallizing course have occurred after long time annealing at 350°C. The recrystallization activation energy is 151 kJmol-1. The ultrafine ferrite grains (average grain size about 317nm), nano-carbides precipitated uniformly were seen in the specimen annealed at 500 °C. Annealing at and above 600 °C resulted in coarse ferrite grains with spheroidized coarse carbides, causing grain growth.