Visible-light responsive TiO 2 -V 2 O 5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO 2 sol and V 2 O 5 sol were mixed to disperse the V 2 O 5 species in the TiO 2 phase at molecular level. The binary sol was then intercalated into interspaces of polyaniline (PANI) by means of in-situ polymerization of aniline. Conglomeration of the TiO 2 -V 2 O 5 clusters during the calcination process was avoided because of the wrap of polyaniline. The surface morphology, the crystal phases, the structure, and the absorption spectra of (PANI), /TiO 2 -V 2 O 5 and the composite catalyst were studied using SEM, XRD, FT-IR, and UV-Vis. The photoactivity of the prepared catalyst under UV and visible light irradiation were evaluated by decolorization of methylene blue (MB) solution. The results showed that the composite catalyst displayed a homogeneous anatase phase, and the vanadium pentoxide species was highly dispersed in the TiO 2 phase. The composite catalyst responded to visible light because of the narrowed band gap. In this study, the catalyst with the sol volume ratio of TiO 2 : V 2 O 5 = 10:1 presented the best photocatalytic activity.