Abstract: The various aspects concerning the placement of expansive-soil embankment and dam are discussedand the basic principle for determining placement conditions （placement water content and dry unit weight of expansive-soil embankment and dam） has been developed.Accordingly, the existing problems resulted from the placement conditions of high water content and low unit weight are analyzed.On the basis of these discussion, it is shown that the ideal placement conditions of expansive-soil embankment and dam should still be the compact of soil with optimum moisture content to the maximum dry unit weight.