The notch sensitivity of a high Nb containing TiAl alloy with duplex microstructure has been studied by monotonic tensile testing using round club-shaped notched and unnotched samples. The results show that the alloy doesn’t exist notch sensitivity for the specimens with U-shape notch of root radius more than 0.5 mm and those with 60° V-shape notch of root radius more than 1 mm. The strength of the notched specimens(RmN) is higher than that of the unnotched specimens(Rm) that the mean coefficient of notch sensitivity(NSR) is larger than 1. The notch sensitivity increases as the reduction of the root radius with the same notch shape. The V-shape notch is more sensitive than the U-shape, and the NSR of the V-shape notch of root radius 0.5 mm fluctuates from 0.98 to 1.03，that is RmN approximates to Rm and easier to cause notch sensitivity.