The 20 years following the World War have seen marked changes in the marketing of manufactured dairy products. Because of this fact, most of the literature on the marketing of such products, based largely on conditions before 1918 or 1920, is now out of date. In recognition of this gap in our present marketing picture, the writer recently published a discussion of the developments of the post-war years in butter marketing² with special emphasis on the increasing importance of large business units as they relate to marketing channels. This bulletin is a similar undertaking with regard to cheese. The aim is to trace the development of concentration in the cheese industry since the War, the changes which this has brought about in marketing channels, and the primary forces responsible for these developments. It is also hoped that this bulletin will serve as a foundation for a more intensive and thorough study of monopoly elements in the cheese industry.