Abstract: In order to obtain basic data for clarifying Population Energeties in the Leymus chinensis grassland ecosystem in Northeast China, determina-tion of calorific values were carried ou ton the Legmus chinensis population which is the constructive vegetation in that grassland. Furthermore, energy storage in population materials on a unit land area were calcula-ted to ascertain its characteristic of energy storage under the natural con-dition.#br#As the results of this study, ear of the Legmus chinensis population possessed the highest calorific value among the various organs, that was 4898.28cal/gDW and living shoot appeared maximum calorific value among the components of the Legmus chinensis population, which was 4711.86 cal/gDW. Most of the solar radiation captured by the Legmus chinensis population was stored up its Under-ground for living through the winter safely and providing sufficient energy to sprouting of its Above-ground at the beginning of the growth season, next year.