Abstract: This article has studied that both of the finish rolling temperature and cooling speeds after hot-rooling influence on the microstructure and mechanical properties. Experimental results demonstrate:1) appropriately reducing finish rooling temperature will improve mechanical properties of 16Mn steel plate. 2) as cooling speeds increasing after hot-rooling, strength of steel increases obviously,when cooling speeds between 5℃/s and 22℃/s. The plasticity and ductility come up to the standard value, at cooling speed of 5℃/s, 15℃/s and 38℃/s, yield-strengths make the grade of 35kgf/mm², 40kgf/mm² and 45kgf/mm²; respectively. Therefore controlled cooling after hot rooling is an effective method for increasing strength-ductility of 16Mn steel.