The ultraviolet-visible absorption spectrum of metal nanometer particle M-Al₂O₃ (M=Au, Ag, Cu, Co, Ni, CuAg) composite film synthesized by electrochemistry method was measured.The experimental results show that the peak of optical absorption spectra of nanometer particle composite film is dependent on the dielectric constant of metal nanometer particle and Al₂O₃ film, and with the increasing of deposition amount of nanoparticle in composite film, the absorption band-edge is red-shifted.It was also found that the properties of optical absorption can also be controlled by adulterating kinds of electrodeposited metal and its alloys.Meanwhile there is a clear absorption peak of surface plasmas resonance of Ag-Al₂O₃ and Au-Al₂O₃ composite film at 360 and 550 nm wavelength respectively.

Key words: metal nanometer particle, Al₂O₃ meso-porous composite film, optical property