As the central concept of the English School, international society contains important economic elements, but the school fails to develop a systematic theory of international political economy. A comparison with the British school shows that the major reason lies in the English School’s long-term tendency regarding disciplinary orientation, sources of theories, and research topics. On its disciplinary orientation, the school maintains that the research object of international relations is the contemporary political relations between states. On the sources of theories, the school lays stress on international law, political philosophy and world history. On the research topics, the school focuses on the political and strategic dimensions of international society and investigates the non-economic relationship between societies, institutions and orders. In light of the incompatibility of ontology, epistemology and axiology between the English School and the British school, it is impossible for them to achieve a deep integration. Therefore, it should be the priority for the English School to have a dialogue with the British school and properly expand its own research agenda for its future development.