Plates of a directional solidification DZ411 alloy with different Ta-content (namely 3%, 3.5% and 4% Ta) were prepared by means of liquid metal cooling directional solidification technique, and subjected to standard heat treatment in atmosphere. Then, the effect of Ta content and heat treatment temperatures (800 ^oC, 900 ^oC, 1000 ^oC) on the fatigue crack growth behavior of DZ411 alloy plates along the direction parallel to the grain growth direction (L-direction), i.e., the direction of directional solidification of the alloy were investigated via electro-hydraulic servo fatigue testing machine by constant load with increment K method in air at room temperature, 450 ^oC and 900 ^oC respectively, while calculating the crack length through flexibility method, as well as field emission scanning electron microscopy with energy spectrometer. The results show that at room temperature, an increase in Ta content leads to a higher fatigue crack growth rate, with the crack propagation path perpendicular to the loading direction and primarily influenced by carbides. The process can be differentiated into three stages: I) the crack passes through the primary dendrite axis; II) the crack bypasses the primary dendrite axis and cuts through the secondary dendrite arm; III) the crack completely bypasses the dendrite axis and propagates along the interdendritic region. At 450 ^oC, the Ta-content has no significant effect on the stable crack growth stage. The crack propagation path is influenced by grain orientation, tending to enter high-Schmidt factor grains and adjacent grain boundaries. At 900 ^oC, an increase in Ta-content results in an overall decrease in the fatigue crack growth rate, with the crack propagation path similar to that at room temperature. However, the influence of carbides weakens, and the crack does not fully enter stage III even at fracture.