Plant functional groups(PFGs) is assemblage of plants which have certain functional characteristics, and is an ecological concept introduced by ecologist in order to study the response of vegetation to climate changes and disturbances. At present the key problem about PFGs still is the plant feature selection applying to classication of PFGs. Taking steppe community in Xilin river Basin of Inner Mongolia as the case study area, 12 sampling plots including 3 steppe community types (Leymus chinensis stppe, Stipa grandis steppe, Leymus chinensis meadow steppe) each with 4 degradation intensities (including undegraed, light degraded, morderated degraded, heavy degraded ) were selected, based on the determination of the caloric values for plant species, a new functional classification method named by Energy Plant Functional Groups (ab. Energy PFGs) was set, which grouped the species into 3 groups including high-energy PFGs, moderate-energy PFGs and low-energy PFGs according to the mean caloric value of species by man-made subsection then the objectivity and feasibility of the the Energy PFGs classification methods were discussed.