Abstract: In this paper, the energy dissipation in particulate-reinforced viscoelastic materials is investigated by means of mesomechanics method. Under the condition of high stress triaxiality, the dissipation can be divided into two parts, i.e., the viscous dissipation energy and the fully interfacial-debonding induced damage dissipation energy. The damage dissipation energy is calculated by neglecting the inertial effect. An approximate method to analyze the viscous dissipation energy is suggested by means of Mori-Tanakas scheme. As an example, the numerical calculations on the two types of dissipation energy are carried out. The effects of loading rate, interfacial adhesive energy, relaxation time of matrix material, average size of particles, and the particle-size dispersity on the energy dissipation are discussed.