Abstract: The paper studies the properties difference of continuous rolling and tempered continuous rolling 10MnNiCr plates.The influences of tempering technology on microstructure and properties of the material are investigated by means of OM, SEM and TEM.The results show that after tempering, the toughness of the steel is enhanced and lamellar tearing is relieved.The pearlite sub-structure changes after tempering of which the cementite shape changes from lamellar to sphericity.The reasons for the properties improvement are sub-structure alteration and dislocation recovery in the steel.