A centrifugally atomized 2024A1/SiC_p composites were extruded to study effect of clusters on mechanical properties, and a model was proposed that the strength of MMCs would be estimated from the load transfer model approach that taken into consideration of the clusters. This model has been successfully utilized to predict the strength and fracture toughness of MMCs. The experimental and calculated results show coincidence and that the fracture toughness decreases with increasing the volume fraction of particles. On the basis of experimental observations, we suggest that the strength and fracture toughness of particle reinforced MMCs may be calculated from; σ_y=σ_mV_m+σ_r(V_r-V_c)-σsub r/V_c, K_IQ=σ_Y((3πt)((r_r/V_r)(r_c/V_c))¹2/)¹2/, respectively.