The surface morphology and V-I characteristics of the Ag thin films deposited on the fractal substrates of α－Ａｌ２Ｏ3 ceramics by rf magnetron sputtering have been investigated. The fractal surface morphology, poor crystallinity and abnormal nonli-near do V-I behavior of the thin films have been observed. The crystallinity of the films deposited on the fractal substrates is improved by increasing the substrate temperature and the thickness of the thin film. The nonlinear V-I characteristics are influenced by the thickness of the thin films, substrate temperature and measu-ring environment.