ZnO/TiO2 nanocomposites with various ratios of the components were prepared by solgel method using titanium isopropoxide and titanium butoxide as titania precursors. Phase formation and photocatalytic activity of ZnO/TiO2 nanocomposites depend on ratio of the components and calcination temperature. The photocatalytic activity in dependence on calcination temperature, phase composition was determined by degradation of methylene blue solution under Hg lamp and solar light imitating illumination. The highest photocatalytic activity was obtained in case of the ZnO/TiO2 nanocomposites containing 99 mol% ZnO and 50 mol% ZnO when hexagonal ZnTiO3 phase was formed. ZnO/TiO2 nanocomposites exhibited enhanced photoactivity under solar light imitating illumination with respect to Hg lamp irradiation.