The black shale of Longmaxi Formation in the Sichuan Basin is a set of important source rock for the large and medium-sized gas reservoirs. The organic matter in the shale absorbs a great quantity of shale gas，so it is of great significance to describe the distribution of organic matter accurately for shale gas reservoir development. Based on the scanning electron microscope（SEM）images of field core samples obtained from shale gas wells at Sichuan Basin in China，the morphological characteristics of organic matter distribution were analyzed quantitatively taking area，perimeter，compactness and elongation as key indicators. The interrelationship of organic matter obtained from samples was characterized by evaluating their distribution distances and angles. The dispersion degree described by a quantitative method was provided and used to denote the organic matter clumps having clustering. Laws between dispersion distance and dispersion angle were summed up statistically. Finally，according to the morphological characteristics and dispersion degree performance，a reconstruction model of organic matter distribution was established based on probability statistics technique and was verified reliable. The organic matter distribution strategy in different scales and their position relationships can be visualized through the model. It can also reflect accurately the strategy of the organic matter area dispersion and characterize quantitatively the heterogeneity of the organic matter. The real internal situation of core can be reflected and a foundation model can be provided for simulating shale internal micro-seepage features.