The N-H related defects at 3124 cm(-1) are found to be acceptors in GaAsN grown by chemical beam epitaxy (CBE), by comparing the concentrations of N-H defects with those of acceptors as a function of annealing condition. The vibrations of N-H defects appear as local vibration modes at 2952, 3011, 3098, and 3124 cm(-1) using Fourier transform infrared (FTIR) spectroscopy. The integrated absorptions at 2952 and 3098 cm(-1) decrease, at 3011 cm(-1) remain small, while at 3124 cm(-1) increases due to the annealing treatment. On the other hand, the concentration of acceptors increases with the annealing time, based on capacitance-temperature (CT) measurement. The densities of N-H defects at 3124 cm(-1) and those of acceptors are almost equal independent of the annealing condition. This result suggests that the N-H defects appearing at 3124 cm(-1) play the role of acceptors in GaAsN grown through CBE.