Abstract:Based on the application practice of cement soils into the highway engineering,the mechanism of the solidification and strength forming process of the humid-plastic cement soils are studied. The cement-soils are classified for highway engineering and the forming method of the humid-plastic cement-soils is proposed. The strength forming process of humid-plastic cement-soils is expatiated based on the characterization of the cement hydration process in cement-water-clay system. The enhancing effect of the additives and mineral admixtures on the humid-plastic cement soils and the suitable additives dosage are studied. The effect mechanism of the additives and admixtures on the strength forming of humid-plastic cement soils is discussed also.