The adsorption behavior was influenced significantly by the types of raw materials, and therefore the common features of adsorption curves between three cements and four emulsified asphalt were compared and summed up to reveal the general law of adsorption for the cement to emulsified asphalt in cement asphalt(CA) mortar. It was found that the adsorption curve could be divided into four stages according to the adsorption characteristics of different stages which were dissolved adsorption, competitive adsorption, accelerated adsorption and saturated adsorption. The synchronous relationship of adsorption and hydration for cement emulsified asphalt indicated that the adsorption behavior had significant correlation with hydration behavior of cement. The influence of emulsifier feeding order on adsorption clearly indicated that the adsorption of free emulsifier and emulsified asphalt to cement showed a significant competition. And the free emulsifier was adsorbed by cement in preference to emulsified asphalt, which revealed the cause of the presence of competitive adsorption stage. The adsorption model of cement emulsified asphalt is proposed based on the observation of characteristics of adsorption curves at different stages and their relationship with the hydration of cement.