Abstract: The volume shrinkage of expansive soils will occur after water loss, which will ultimately lead to cracks. Due to which it has an important impact on its Mechanical and Engineering properties. Therefore the research on expansive soils shrinkage has been paid much attention and made many progress. In this paper, the basic characteristics, main influencing factors, shrinkage mechanism and shrinkage model of expansive soil are introduced along with existing problems and shortcomings are briefly analyzed. It is concluded that the study on shrinkage characteristics of expansive soils should be deepened from the following aspects: the relationship between mineral composition and content; shrinkage characteristics of expansive soils; the relationship between crystal structure and shrinkage mechanism of expansive clay minerals; and the influence of structure on shrinkage characteristics of expansive soils.

Key words: Expansive Soils； Contraction Mechanism, Contraction Model, Mineral Compositions