Abstract: As geometry of nature and a powerful mathematics tool in nonlinear analysis, fractal theory has been applied in a very wide field of science and technology and will attract more and more attention in the future. In this paper, the authors presented the basic definitions of fractal dimensions and reviewed the applications of the fractal theory to agricultural and food systems. Firstly, the examples were discussed to illustrate the application of fractal theory to characterize soils, soil water relationship, and some physics, chemistry and biology phenomena in soil media. Secondly, the fractal analysis of food materials was introduced, including the fractal dimensions, fractal surface structure, fractal aggregation and microstructure of foods, as well as the food processing and quality control. Thirdly, the fractal analysis and modeling for plant and animal systems, including the root systems and the animal activities were summarized. Finally, discussion and prospecting on the fractal analysis were given.