In this research, the effects of B, O and B&O−doped on the SO2 gas adsorption on the surface of the (4, 4) armchair AlNNTs are investigated by using DFT method. From optimized structures the geometrical and electrical properties, adsorption energy, gap energy, global hardness, electrical potential, HOMO−LUMO orbitals, density of states (DOS) plots, electrostatic potential (ESP) plots and NMR parameters are calculated and are analyzed. The adsorption energy of the all adsorption models is negative and exothermic in thermodynamic view of point. Doping of B atom increases the adsorption energy of nanotube/SO2 complex, whereas doping O atom decreases the adsorption energy of system. The positive values of ΔN of nanotube/SO2 complex indicate that the charge transfer occur toward to the SO2 gas, which suggests that their electronic properties of system could be notably changed upon chemisorption’s of SO2. The NMR results reveal that the isotropy the electrostatic properties of nuclei are mainly dependent on electronic density at their sites, therefore because of the SO2 gas adsorption, the electronic densities of nuclei and the CS tensors undergo changes