The effects of silicon content on the microstructure and mechanical properties of SiCp/Al-Si composites produced by spray deposition were investigated with 7, 3 and 20% Si.The optical microstructures indicate that the average size of eutectic Si and primary Si in the composite containing 20% Si (3.44,7.85μm) is higher than that the composite containing 13% Si (2.51, 5.85μm) and 7% Si (1.95, 0μm).Otherwise, the increase of the Si content results in an increase in the volume fraction of the primary Si and the eutectic silicon phases, and a decrease in particle distance between Si and Si phases.The tensile results show that the as-sprayed composite with a higher Si content displays an increase in the elastic modulus, yield strength and ultimate tensile strength, but a decrease in elongation.Both the SiC particle/matrix debonding and Si decohesion are observed in the three composite, while primary Si particle cracking is dominate in the composite with 13% and 20% Si.The fracture reveals an increase in the degree of the brittleness and the cracking tendency of the primary Si particles due to the Si content increasing.