The effects of cycle temperatures on the thermal fatigue crack growth of three kinds of superalloys were investigated. The experimental results show that the crack growth rate increases with the rise of cycle temperature. Optical Microscopy (OM) and Scanning electron microscopy (SEM) observations reveal that multiple small cracks primarily initiated at the notch tip in any temperature range. Subsequently, only one or two small cracks can continue to grow, and finally form the main cracks. The crack growth behavior varies distinctly for different alloys. In general, thermal fatigue cracks propagate along a preferential direction with the dendrite growth direction in single crystal superalloy, but along the interdendritic region for the Mar-M002 alloy.