Electroless Cu plating process has been studied in order to coat three kind of ceramic particles of different size. It is found that the amount of complexing agent addition in the plating bath should be adjusted corresponding to the size of the coated particles to obtain coatings with acceptable quality. However, all the three kind of ceramic particles show more or less the same behavior during plating. Mechanical properties of the SiCp/Fe、TiNp/Fe and TiCp/Fe composites containing reinforcing particulates with and without Cu coating respectively were measured comparatively. Results show that the mechanical properties of all the three composites with Cu coated reinforcing particles are superior significantly to their counterparts. However the highest enhancement of tensile strength induced by Cu coated particles was observed for the TiNp/Fe composite, but not for the SiCp/Fe composite, which showed the highest tensile strength among the three composites with raw ceramic particles without Cu-coating. It is clear that the defects at the interfaces of particles and matrix should be a determining factor affecting the tensile strength of the composite. Similarly, the larger content of particles with Cu coating in the composite is, the higher enhancement in mechanical properties may be expected. Moreover, microstructure analysis also indicates that the copper coating on particles could effectively avoid the direct contact of particles and reduce defects formed at the interfaces between the particles and matrix.