Abstract:When road is put into use after completion,the additional stresses on the soft subgrade soil will be changed,which are composed of static stress and dynamic stress. Therefore,the post-construction settlement of soft subgrade soil should include two kinds of stresses caused by the embankment gravity and the motor vehiucles. The advance in post-constructin settlement of the soft subgrade soil will be studied,which includes the different mechanics behaviors and characteristics of subgrade soil under static load exerted by the road embankment and under dynamic load induced by the motor vehicles. Then,the major problems in the research of post-construction settlement of subgrade soil are presented;and the six deformation ingredients which lead to post-construction settlement are proposed. Finally,the treads of development of the post-construction settlement of subgrade soil are put forward.