We consider a model of isotropic composite media with random mechanical properties of the microstructure. We define the composite granular structure by the spherical regions, where statistical dependence of modulus of elasticity can be estimated using experimentally determined moment functions for mechanical properties of the microstructure. Applying the integral operator equation, which includes the second derivatives of the Green tensor, we obtain the algorithms for calculation of multipoint distributions of components of tensors of random microstructure strains and stresses. Application of the real moment functions became possible after generalization of the methods of solution for the composite materials with continuous distribution of elastic characteristics (the microstructure of these materials is not statistically homogeneous).