Magneto-transport measurements have been carried out on a Si modulation-doped Al 022Ga078N/GaN heterostructure in a temperature range between 1 5 and 25 K under magnetic field up to 10T. Striking beating patterns in magnetor esistance vs magnetic field are observed in the vicinity of a specific temperatu re. Theoretical simulation is performed and the comparison between numerical sim ulations and the experimental data reveals that the beating patterns are due to the interference of the magneto-intersubband scattering and the SdH oscillator o f first subband.