The microstructures of sprayed SiCp/Al composite fabricated by thermal spraying technique by optical microscope (OM)scanning electronic microscope (SEM), transmission electronic microscope (TEM), X-ray (diffractometer) XRD, selected area electron diffraction (SAED), energy dispersive spectrum (EDS) techniques, were investigated. The composite consisted of SiC and Al, along with single crystal Si and amorphorous Si, and tiny Al2O3. The interfaces between SiC particles and Al matrix bonded well, and tiny reactants like Al2O3 were found near the interfaces. The mechanisms of chemical reactions during sprayin were discussed g. The nano-Al grains and particles were observed in the sprayed composite. The formation of nano-Al grains and particles of SiCp/ Al composites were explained. It has been found that Several interface relationships existed in the sprayed composite.