In concurrent object-oriented languages, inheritance and concurrence are the primary features. But concurrent objects and inheritance have conflicting characteristics thereby simultaneously use of them causes the problem, so called inheritance anomaly, which requires code redefinition of inherited methods to maintain integrity of objects. In this paper, to solve this inheritance anomaly without broken of encapsulation, we introduce the state abstraction concept and map internal states of the encapsulated object into abstract slates. And also, we design the inheritance interface for efficient inheritance. Through the inheritance interface containing abstract state set, though redefinition of the method is incurred, we can remove the influence of other classes in inheritance hierarchy. And also, we can solve the inheritance anomaly problems.