The present monograph analyses some topics in the pure theory of international trade. They are all concerned with the structure of production to which I have paid particular attention after the completion of my Ph.D. course at University of New South Wales. In my Ph.D. thesis, I studied extensively the production possibility sets under Professor Murray C. Kemp, who kindly contained all my products in his edi ting book, Production Sets (Academic Press, 1982). Since then, I have developed the work to the studies of international trade. The present volume is organized with these studies. Therefore, although the draft was written at Nagoya City University, the works at Tokyo Metropolitan Uni versi ty in 1980, Kobe Uni versi ty of Commerce from 1981 to 1984 and University of New South Wales in 1985 were also substantial. All uni versi ties provided me with comfortable circumstances and good colleagues for my academic work.