Mineralogical characteristics, formation environments and environmental mineralogical significance of uranium acyl arsenate minerals in China are discussed systematically in this paper. They are supergene minerals occurring in oxidized zones of uranium deposits and assuming green-yellow colors. This kind of minerals can be used as one of the mineral indicators in search for uranium deposits. They are mainly composed of ~(3-) and ~(2+), in which As and U are known as poisonous and harmful elements causing environmental pollution. These elements are very active and have strong capacity of decomposition and migration in different acid, alkaline and oxidation-reduction media. Decomposition, migration and diffusion of arsenic and uranium result in serious extensive environmental pollution in mines and their downstream areas. Relatively stable uranium acyl arsenate minerals can be formed under the condition of weak acid to neutral media through combining ~(3-) with ~(2+) and other metallic cations. This process can reduce transportation and diffusion of uranium and arsenic and relieve to some extent their harmful effect on environment.