Abstract: The problem that large area is occupied by dredged materials and the strength of solidified soil is developed slowly has become urgent in geotechnical engineering. The performance of solidified dredge treated by sulphoaluminate cement which is used in sludge solidification/stabilization (S/S) practice, and the early-strength mechanism based on water transfer are studied. For the dredged materials from Taihu Lake treated by the sulphoaluminate cement and the ordinary portland cement, the unconfined compressive strength (q_u) and the failure strain of the solidified soil and the amount of water transfer are measured. The test results show that the sulphoaluminate cement has a good performance of early strength in solidification. The early-strength mechanism is the formation of more crystalline ettringite, that can be quantified by mineral water, which plays a key role in the hydrating reaction.