To evaluate the effect of graphene inclusions on deformation characteristics of nanocomposite "metal-graphene" the finite element analysis of representative volume deformation followed by homogenization of the mechanical properties deformation is performed and the dependence of effective modules and plastic flow on the concentration of graphene inclusions is studied. It is shown that the influence of inclusions on the modulus of elasticity and plasticity limit of the nanocomposite is not significant. Graphene inclusions effect on strength and fracture toughness of the composite "(nano) metal-graphene". The results of finite-element simulations indicate that in the nanocomposite a decrease in stress concentration in vicinity of the crack tip is observed when approaching the crack tip to the graphene inclusion enable.