This paper aims to establish the relationship between formal concept analysis and rough set theory.The following results are obtained:(1)a derivative formal context of an information system can be induced by the notion of nominal scale and the technique of plain scaling in formal concept analysis;(2)some core notions in rough set theory such as partition,upper and lower approximations,independence,dependence and reduct can be reinterpreted in derivative formal contexts.In addition,the limitation of rough set theory to data processing is analyzed.The results presented in this paper provide a basis for the synthesis of formal concept analysis and rough set theory.