In order to utilize the Yellow River sediments,silt is characterized by instruments for silt properties. The silt in the lower reaches of the Yellow River is also solidified using a hydrothermal processing method,and investigated the effect of addition content on flexural strength of solidified bodies and its hardening mechanism.The analytical results show that the particle size,chemical and mineralogical compositions of the silt in the upper,middle and lower reaches of the Yellow River are almost the same and the amount of heavy metals dissolved from the silt is below the regulatory levels for the environmental quality standards for soils of China.The flexural strength of solidified samples reaches 17MPa.The strength development is shown to depend on the formation of tobermorite,and the more the tobermorite,the higher the strength.