In spite of the many important changes which have taken place in the marketing of manufactured dairy products since the World War, no analysis which takes adequate account of these changes is yet available. While post-war text books on agricultural marketing have treated the marketing of manufactured dairy products in a very broad manner, their major emphasis has been on cooperation, with almost complete oversight of the marked and increasing importance of very large private business units in the distribution of the several dairy products and the changes in marketing channels under way. It is the aim of this study to attempt partially to fill this gap by a reconsideration of the marketing of butter with special attention to changes in its channels of distribution, concentration in the butter industry, and the various supplementary and complementary relationships involved in the recent increased diversification of dairy products distributed.