The integration of deductive database and object database results in deductive object database which has capacities of deductive query of deductive database and strong modeling of object database. DOL (deductive object base language) is designed as a deductive object base language. It supports class, object identifier, complex object, partial set, inheritance and overriding. A immediate consequent operator, similar to tradition's, is defined based on two operators: compact operator and overriding operator in this paper. In addition, a fixed point semantics is analyzed.