Abstract: An approximate technique is used to calculate the absorption coefficient of absorbers containing a cavity and made of material with scattered spherical particles.The technique is based on a self-consistent theory and a method of calculating equivalent mechanic parameters of an absorber containing a cavity.The simulation results show that the absorption capability can be improved if the material of an absorber contains some particles,and the degree of improvement is related to the type,size,shape,porosity,and probability density of particle distribution,and if the absorber is made of a particle and cavity-loaded material,its absorption capability is much better at low frequencies.It is concluded that absorption capability of an absorber is controlled by the parameters of inclusion and the structure of cavity.