In this research, aluminum-based composites reinforced by different steel wires were synthesized using conventional infiltration process at 0.5 and 1.5 volume percent of reinforcement. Four kinds of interconnected wires including stainless steel wires, low carbon steel wires, aluminized steel wires and Ni-P coated steel wires with different meshes were applied. A failure happened in the synthesis process of stainless steel wire reinforced composite because of wires mesh size. The mesh size of stainless steel wires was so small that aluminum melt did not infiltrate into the mould properly. A 5-8 µm layer of Ni-P coating was deposited on steel wires using Electroless Process. Ni-P coating on wires was evaluated by optical and scaning electron microscopies. Tensile and micro-hardness tests were applied on composite samples to evaluate mechanical properties. Furthermore, Microstructural properties of composites were studied by optical and scanning electron microscopies and EDS analysis. The results showed that tensile strength of Ni-P coated wire reinforced composites were improved in comparison with monolithic samples. Also no noticeable reduction in elongation of Ni-P coated wire reinforced composites was observed. The tensile tests of aluminized steel wire reinforced composite showed the lowest elongation and the highest tensile strength among other composites. Intermetallic phases of Fe-Al, produced as a result of high-temperature contact of Fe and Al, are brittle and hard. Microstructural results showed the presence of intermetallic phases such as FeAl 3 , Fe 2 Al 5 and Fe 3 Al in the interface of aluminum/Steel wires. It seems these phases improved the strength of the composites reinforced by aluminized steel wires. It was observed from EDS analysis that Ni-P coating hindered the diffusion of Al and Fe atoms resulted in a Fe-Al intermetallic free interface. The effect of intermetallic phases in interface on the mechanical properties was investigated by heat treating the aluminized steel wire reinforced composite for 6 hours at 500?C. In this research, it was resulted that presence of Fe-Al intermetallic phases increases strength and hardness and also decreases considerably elongation of composite. In contrast, presence of Ni-P coating in interface will lead to improvement of strength and maintaining ductility of composite. Key Words: Aluminum, Steel Fiber, Metal Matrix Composite, Infiltration, Ni-P Coating, Mechanical Properties, Interface.