Abstract: Due to the particularity of the formation process of large-thickness compacted fill in Yan'an New Area,there is no specific evaluation basis and criterion for the uniformity evaluation of its foundation in current codes.On the basis of the engineering properties of compacted fill and the influencing factors of differential settlement, a concept of differential settlement sensitivity of compacted fill foundation is proposed innovatively,and a concrete method to determine the uniformity of compacted fill foundation is introduced,which is convenient to evaluate the uniformity.It provides a basis for general layout of buildings,foundation treatment and foundation design.The non-uniform foundation with large thickness compacted fill should be treated pertinently,and necessary structural measures should also be carried out.Settlement observation of buildings should be strengthened for thorough long-term study.