The meso-structure of rock affects its energy behavior during loading process. From three meso-characteristics, that is, mean strength of rock element, homogeneity, and meso-characteristic scale, their influential rule involving five characteristic energy parameters as well as four energy characteristic indexes is discussed. The results show that (1) with the increasing the mean strength of rock element, the input energy density and elastic energy density go up nonlinearly while stress ratio is same; the dissipated energy after peak strength changes a little, about 500～2000J/m³; conversion rate to elastic energy decreases; energy characteristic indexes of rock sample increase exponentially. (2) As the homogeneity raises, the input energy density and elastic energy density before peak strength increase linearly; the dissipated energy after peak strength reduces; more and more input energy translates into elastic energy accumulated in rock; the energy characteristic indexes enlarge linearly. (3) The larger the meso-characteristic scale is, the more the input energy and the elastic energy with different ranges is; the more the dissipated energy after peak strength is, the lower the conversion efficiency into elastic energy is. The energy characteristic indexes decrease by a large margin when meso-characteristic scale is smaller than 1mm and decrease only a little when meso-characteristic scale is larger than 1mm.