Fatigue crack propagation behavior of an advanced Zr-Sn-Nb alloy NZ2 with different hydrogen contents (0, 200, 450, and 730 mg/g) was investigated by standard M(T) specimens. The results showed that stable crack propagation behavior obeyed the Paris Law, i.e. da/dN=C(DK)n, whether the hydrogen content is high or low. But the power exponent n of the Paris Law was decreased with the hydrogen content increasing; the increment of hydrogen content can decrease the ductility of NZ2 alloy and enhance the fatigue crack growth rate, especially when the specimens have higher hydrogen content.