This paper proposes the intuitionistic fuzzy rough set models based on tolerance relation in intuitionistic fuzzy information system,in which the target concept is described from two aspects of optimistic and pessimistic,which is a new approximation method for target concept.In addition,some relationship is found between optimistic and pessimistic approximations.The approximate accuracy of optimistic intuitionistic fuzzy tolerance rough set is higher than that that of the pessimistic one according to the definition of approximation accuracy.Finally,the empirical analysis is provided,which verifies the effectiveness of the presented method.