Abstract: Huge amounts of dredged clays are inevitably produced during the processes of river dredging and widening and port construction and expanding. Consequently, how to deal with the great amounts of dredged clays has become a hot issue in hydraulic engineering and geotechnical engineering. It is usual to treat the dredged clays with solidification method. The treated soils are usually used for engineering construction. So its mechanical properties should be considered as engineering materials. In order to study the compression properties and the structure yield stress, a series of compression tests with different mixing proportions are performed on the soils. As many natural sedimentary structural clays and cement-stabilized soil, there is a notable structure yield point for all compression curves of the solidified soil in many one-dimensional compression experiment results. When the upper load is less than the structure yield stress, the compressibility of solidified soil is very small. But the compressibility increases dramatically once the upper load is over the structure yield stress. Some factors affecting the structure yield stress are analyzed. Expression about the relationship between Py and qu is proposed by comparing the results of the one-dimensional compression tests and the unconfined compression tests. Compression properties of the solidified soil are significantly different between pre-yield and post-yield states, which is very useful for its application in engineering. The upper load cannot exceed the structure yield stress to avoid the sudden destruction without warning.