The environment consciousness or conception is introduced into the field of surface engineering of metallic materials in this paper. From the angle of environmental protection, the surface strengthenning processes are studied quantitatively. The environmental loading value(ELV) of different types of surface treatments are assessed quantitatively, after analyzing the basic data of surface strengthenning for different steels. The results show that the same steel has different environmental loadings for different surface strengthenning processes, and the same treatment can result in different environmental loadings for different materials. Finally, a method of the comprehensive assessment for surface treatments is proposed, including three indexes: ELV; HV/ELV; and d /ELV(HV: hardness, D: hardened depth).