Fractal dimension values of each landscape of the mosaic structure of land use and land cover are calcu- lated at Wenchuan county in Sichuan province. Properties of fractal dimension of each landscape and their changes are discussed. It is indicated that the mosaic structure of land use and land cover has statistical self-similarity and its fractal dimension value is a kind of random fractal geometry by the research. Bigger fractal dimension value in- dicates that the spatial configuration of a landscape is more complex, whereas its spatial configuration is simpler. The stability index of a landscape bigger than zero means that the stability of landscape spatial configuration under complex state. The bigger the value of SI is, the more stable.the spatial configuration of a landscape is vice verse. The stability index of a landscape smaller than zero means that the stability of landscape spatial configuration un- der simple state. The smaller the value of SI is, the more stable the spatial configuration of a landscape is; vice verse. The spatial configuration of a landscape gets more and more complex if the fractal dimension value increases with time, whereas its spatial configuration gets simpler and simpler. The quantity fractal dimension is a compre- hensive index to study landscape pattern of the mosaic structure of land use and land cover.