Quenching and partitioning（Q&P）treatment was applied to cold rolling sheets of 409L and 410S ferritic stainless steels，which resulted in a multiphase microstructure of ferrite， martensite and retained austenite. The austenitizing temperature，quenching temperature and partitioning time were optimized to obtain the maximum martensite and retained austenite. Compared to normally annealed and quenching and tempering（Q&T）treated sheets，the Q&P treated one exhibited the best combination of strength and elongation，a continuous yielding and moderate n- value and r- value，which satisfied the requests of high strength and well formability and can substitute advanced high- strength steel in manufacture of automobile structural parts.