Abstract: Aim To analyze the influence of inclusion's spatial distribution and orientation on plastic properties of composites. Methods The micromechanical model was constructed on the basis of the Ponte Casteneda and Willis' elastic model and secant moduli method of second order stress moment.Results and Conclusions An analytical method was proposed, which enables one to analyze the influence of inclusion's orientation and spatial distribution on the eastic plastic behavior of composites. Results applied to a SiC/Al system show that for particles reinforced composite the spatial distribution has minor influence on the elasticplastic curves of the composite. When applied to the composites with 2 and 3 dimensional randomly oriented inclusions, Mori Tanaka's method is shown to be the case where the ellipsoids characterizing the inclusion's distribution take the same form and orientation as the inclusions, which can not be realized within the PCW's microstructures.