The microstructure of Ag/TiO2 and Ag/Ti/TiO2 multilayer system are investigated by AFM and TEM, and their interfaces are analyzed by the means of spectroscopic ellipsometry (SE). The results show that the multilayer has a sharp interface without interdiffusion and interface reaction products. AFM surface roughness analysis indicates a 2-nm titanium transition layer can improve surface quality of silver films, because it is enabled to change silver island dimension and distribution and improve coverage of silver films on Ti/TiO2 substrate. This can be attributed to titanium ׳s strong oxygen affinity and good wettability to titanium dioxide. The optical properties test of TiO2/Ag/TiO2 multilayer demonstrates surface plasma resonance (SPR) absorption shifts towards long wave region with the increasing of the total thickness of dielectrics.