Abstract: By comparing geotechnical properties of sediments of the same ages, it has been found that there are a great difference between the soils from the north of Jiangsu and the Yangtse River delta. The authors then assess the deposition environment and the dynamic conditions and the origin of deposits in the two areas at the same ages. The results indicate that the physical and the mechanical properties of soil are closely related to the deposition environment and dynamic conditions and the origin of deposits. Therefore, understanding conditions of the soil deposition is a key to characterization of the soils geotechnical properties.