In this paper,effects of chemical composition and hot rolling process on microstruture and mechanical properties of 15 MnV steels have been investigated in laboratory.The results show that,if only composition and hot rolling process are controlled suitablly,reducing manganese content of steels by 1.2% is possible.The suitable composition and hot rolling process compatible with that 15 MnV steels after reducing manganese content still meet specified demanl for mechanical properties are arrived.