The improvement of urbanization level and the imperfection of waste treatment infrastructure have caused the problem that informal garbage dump become prominent problem in China. With the development of high resolution remote sensing images, the fast monitoring and management of informal garbage dumps become possible. The informal garbage dumps in Beijing are monitored by SPOT-6 image, and the rapid and accurate grasp of the number, position and size of the informal garbage dumps are identified by the establishment of the interpretation key using multivariate data. And then it is classified by the established interpretation key. Irregular garbage sites are uneven in shape and complex in composition, which leads to their atypical features in images. Visual interpretation and classification are more suitable for other methods.