Abstract: The Charpy impact test、hardness test、microstructure and morphology analysis of impact fracture by SEM were introduced to research the difference of impact toughness on 25Mn, which were in the state of hot-rolled, normalized and quenched & tempered. The results showed that the changes of load, deformation and energy exhaust in different stage of deformation and fracture could be gained by Charpy impact test. 25Mn in quenched & tempered has more deformation resistance and deformation property than which in other staties. The total impact works was 6J higher than which in normalized in average, however, the crack propagation works was 16.78J higher in average. Ductile-brittle property of the material can be estimated by the analysis of crack formation works, crack propagation works and fracture morphology on samples.