To understand effects of mineral admixtures on fatigue behavior of concrete,fatigue behavior of concrete with 30%,50%(by mass) fly ash and with 30%,50%,80%(by mass) blast furnace slag under flexural fatigue load were tested.Results show that fatigue strength corresponding to 2 000 000 cycles increases with the increase of cement replacement level by mineral admixtures.Mineral admixtures can exert benefitial effect on high-cycle fatigue behavior of concrete for the improvement of interfacial transition zone,as for low-cycle fatigue behavior,effect of mineral admixtures depend on their influence on concrete strength.