Abstract: The aluminum matrix composites reinforced by short carbon fiber were prepared in non-vacuum furnace by the method of liquid state mechanical stirring casting.The C/Cu composite fiber was treated with H₃BO₃ after the carbon fiber was coated with copper in the electroless plating and electro plating process.The effects of dispersion of carbon fiber in the composite, existing state of copper plating and tensile properties of the composite were investigated. The results showed that the oxidation rate of copper decreased obviously and carbon fiber was uniformly dispersed and undamaged in the composite.The mechanical properties of the composite were not influenced by the H₃BO₃ added.The tensile strength of the composite increased with the increasing content of carbon fiber, which was 50% higher than that of the matrix material. However, the plasticity of the composite decreased obviously.