Abstract: To investigate the relationship between the deformation and energy characteristics of the rock mass and the stress state， triaxial cyclic loading and unloading tests on granite under five types of confining pressure were carried out. Based on the stress-strain curves， the elastic modulus and energy density of the granite were calculated during cyclic loading and unloading， and the influence of the stress state on the evolution of the elastic modulus and energy was analyzed. The results show that the axial modulus of elasticity increases with the increase of the confining pressure， and increases first and then decreases with the increase of the axial stress. The axial modulus of elasticity shows a good quadratic function with the maximum and minimum principal stresses. The energy density and the proportion of elastic energy (the ratio of elastic energy to total energy input) increase significantly as the confining pressure increases， and the energy storage capacity of the rock increases. The proportion of elastic energy increases first and then decreases as the axial stress increases. The decrease in the proportion of elastic energy is the stage of increased damage to the rock， and the increase in the confining pressure prolongs the process of damage evolution. Finally， the correlation between stress state， rock mechanical parameters， and energy state is discussed.

Key words: rock mechanics; triaxial cyclic loading and unloading; elastic modulus; energy evolution characteristics; energy storage levels