Highly dispersed silver sulfate nanoparticles deposited on ZnO nanoflakes (ASZ) were successfully prepared by a simple solvothermal method with different silver contents. The prepared 3ASZ composite shows improved photocatalytic activity for rhodamine B degradation under UV-vis light irradiation compared with pure ZnO, Ag2SO4, and commercial TiO2 (P25). The remarkable photocatalytic activity for ASZ composite maybe due to the synergistic effects between photo-reduced Ag and SO42- on the surface of ZnO nanoflakes, which promote efficient separation of electron-hole pairs.