The experiment of strength and carbonation depth were compared respectively with the ratio of 0%、10%、20%、30% of fly ash(FA) and the same ratio of grout volume,to research the influence of the content of FA to the mortar.The result shows that with the certain water-binder ratio(W/C),the fluidity of cement mortar does not significantly reduce when FA increases;the strength of mortar with FA decreases with the increase of the FA in the early stage while it catches up with gradually and surpass that of mortar without FA;the carbonation depth of cement mortar increases with the increase of the amount of FA,and exposure time.