Abstract: During construction,intensity parameters of unsaturated soil have some changes,but some mechanical indexes of original stated soil are adopted in design,which must be bring about some errors.In order to resolve this problem,Some triaxial tests to simulate the practical stress paths of unsaturated soil are introduced,the affection and changed properties of cohesion and inner frictional angle of unsaturated soil disturbed by construction is researched.On the basis of research,the reasons of these changes is analyzed.