The exposure of medicines to environment and its eco-hazards is a research focus in the world, and veterinary medicines used largely in animal food industry have become an important sources of the pharmaceuticals in environment. Most of veterinary medicines taken by animals are shown in their original forms or various metabolites in animal excrement. In this paper the residues, degradation and its affecting factors of veterinary medicines in animal excrement are reviewed, and the influence of the residual veterinary medicines on the compost process of animal excrement is also introduced.