Abstract: Normal sedimentary soil generally has the characteristics of original structures. Up to now, the most soil constitutive models are developed and built up based on the non-structure soils. If they are directly used to describe stress-strain relations of structure soils, a great difference can be produced between the measured value and the calculated value. This paper is based on the modified Cambridge model. The stress-strain relationship is established considering the influence of original structure property of the structural soft dredger fill. Compared with the modified Cambridge model, the new model only increases the number of parameters. They can be obtained through the conventional triaxial test. The types of parameters are unchanged. The triaxial compression test are conducted of the structural dredger fill which are treated by vacuum preloading method in Tianjin Binhai new area. Compared with the test value and the simulation value, the new model can consider the effect of original structural impact.