Abstract: The tensile strength,yield strength and notch toughness of Q420 angle steel produced by V-N interalloying method were improved evidently and integration properties were better. The renson was analyzed and discussed through methods of chemical composition,mechanical property and microstructure etc. The result showed that V-N interalloying method could arrive of microstructure refining and precipitation strengthening. The integration properties of strength and toughness of Q420 angle steel were improved to meet better consumer needs.