With the accelerating process of urbanization,the technology of Remote Sensing(RS) can supply the direct,accurate and synchronous information for the change detection of urban land use.Ontology is a definite description of conceptualization.It can be showed closer to cognitive model and easier to be understood and shared; it can be also operated by the computer's formal language to express a tangible goal in the field of the concept and its implication semantics.As a result,with the existed researches analyzed and learned,〖JP3〗the thought of Ontology and Semantic are introduced to the expression of the RS images.Moreover,semantic model and interpretation framework of RS images for urban field based on Ontology are built up in this paper.Then the semantic model in the processing procedure of urban RS images was formed to improve the accuracy and efficiency of RS technology in urban field.