Abstract: The Influences of subcritical annealing on the austenite transformation kinetics in the intercritical annealing of Fe-C-Mn dual phase steels are studied by means of OM, SEM. And using EDX, WDS technology, Mn-partitioning in carbide during subcritical annealing are measured. The results show that subcritical annealing is believed to prompt the Mn-partitioning to carbide, and to form a Mn-rich austenite during the intercritical annealing. Therefore, the hardenability of austenite is increased during batch annealing. It should be applicable for batch annealing processing of dual phase steels.