Abstract: Nanosized SiO2/ TiO2 particles were prepared in two microemulsion systems, Triton X-100/ n-hexanol/ cyclohexane/ water and CTAB/ n-hexanol/water respectively. The particles were characterized by TG-DSC, XRD, TEM and FT-IR. The transformation temperature of the crystallite was analyzed by TG-DSC. The crystalline phases of the particles were recognized by XRD analysis. The morphology and size of the particles were observed by TEM. Fourier transform infrared spectroscopy (FT-IR) of the product was compared with the commercial titania. The performances of the prepared SiO2/ TiO2 particles with CTAB and Triton X-100 as a catalyst in degradation of basic violet by near UV light were evaluated and compared, and the results show that the photo absorptivity, the degradation activity and COD removal capability to basic violet of the product from the CTAB system are very well.