Abstract: Numerical simulations of effect of polarization on current characteristics of AlN/GaN resonant tunneling diode（RTD） are presented,employing self-consistent Schrdinger and Poisson equations in the model of semi-empirical tight binding method.The simulated current-voltage characteristics show strong asymmetry effects and the position of resonant voltage is changed due to polarization charges.Those simulated results are consistent with experimental data.As the polarization charges increase,only one resonant tunneling phenomenon or not can be observed in a certain sweeping voltage.