Öz That the philosophical quality of the idea of duty, canstitutes the camman conscious of society is the direct faetar that effects the progress and development of the community. In this essay, we attempted to compare the idea of duty based on Islamic and Westem thought. Because of the most important place and inf1uence in Western thought, Kanrs moralfethical duty is centered. Both systems of thought show parallelism from view point of having the persons the conscious of duty. But they separated each other from view paint of the origin of duty, its subject, categorization of duty and the purpose that regarded performing duty. it can be said that comparing with Kant's philosophy Islamic legaı thought is in more progressed level.