This study advanced the comprehension of patent management by analyzing and comparing patent management and its organization of several companies. It was 1890s when General Electric and Westinghouse Electric internalized patent management and organized patent department. The reasons for formation of patent department were expansion of research and development activities and increase of inventions. Patent management of those companies was administrated by professional patent attorneys. This study also makes clear that, both companies established local patent department in the countries where they entered into, however, the ways and the organization of it were quite different among them.