The temperature stability of mechanical properties and volume of CA mortar（cement asphalt mortar） was studied. Results indicate that the compressive strength and elastic modulus of CA mortars decrease when temperature increases from -10℃ to 40℃. The compressive strength of CA mortar with SBS modified asphalt emulsion decreases significantly with increase of temperature when mass ratio of asphalt emulsion to cement is higher. The decrease range of compressive strength of CA mortar with asphalt emulsion is greater than that of CA mortar with SBS modified asphalt emulsion at same mass ratio of asphalt emulsion to cement when temperature increases. The thermal expansion coefficient（TEC） of CA mortar decreases with increasing mass ratio of cement to sand and curing time, whereas it increases with increasing water amount and volume ratio of asphalt emulsion to inorganic material（cement and sand）. After asphalt emulsion is modified, the TEC of CA mortar decreases, the temperature stability of volume of CA mortar is improved, and SBS modifier is the best for the improvement.