Sputtered TiO2/SiO2 multilayer films were studied by Fourier-transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD), and their bonding structure and crystallization were compared with TiO2-SiO2 composite films. The thickness ratio TiO2/SiO2 of the multilayer films was fixed at 1:3, and the TiO2 monolayer thickness dt was varied from 0.3 to 60 nm. With decreasing dt, crystallization of TiO2 was lost, and the IR absorption at 930 cm-1 increased. These results suggest that SiO2 and TiO2 were changing their structure to a Ti(x)Si(y)O(z) composite state with decreasing dt. In the intermediate between anatase crystal and noncrystal, TiO2 of the multilayer films showed a different orientation from that of the composite films.