Abstract: A cyclic annealing process of phosphorus containing low manganese steels plates in bell-type furnace, being aimed at dual phase microstructures, is studied. The influence of phosphorous on microstructures and mechanical properties of cyclicly annealed steel plates is investigated also, which provides good references for the production of P containing steel plate. The experimental results show that the steel plates containing -2% Mn and (0.1-0.13%) P, which are treated under a cyclic annealing process at 680℃ for 8h follwed by 730℃ for 4h, then furnace cooled to 400℃ and air cooled below 400℃ can meet the mechanical property requirement of T.S. L-540MPa, El.>27% and good drawing quality.