Aerosol particles suspended in the air not only affect the visibility of atmosphere,but also harm human health.Combustion of fuels is an important source of particulate matter in the atmosphere.The mutual reaction among combustion products is the source of secondary particles.HOSO is a key intermediate in the combustion of fuels containing sulfur and plays an important role in the field of atmospheric and combustion chemistry.The HOSO was formed via the reaction of OH and SO or SO2 and H.It is important to investigate the role which HOSO plays in atmosphere.The existence of nitrogen dioxide,water and ammonia from atmosphere will react with the HOSO.Geometries optimizations and frequency computations were performed at the B3LYP/6-311+G(d,p)level and ground-state potential energy surface,reaction Gibbs free energies and reaction enthalpies were also calculated at the CCSD(T)/aug-cc-pvdz//B3LYP/6-311+G(d,p)level.The reaction of three gases NO2,H2O and HOSO may proceed HOS(O)ONO-H2O,HOS(O)NO2-H2O,HOS(NO)O2-H2O,NO2-H2O-HOSO,HOSO-H2O-NO2complexes.The complex HOS(O)ONO-H2O and HOS(O)NO2-H2O all finally decompose to H2SO3 and trans-HONO by the energy barriers of-16.6 and 7.3 kcal/mol,respectively,the energy bases on the NO2,H2O and HOSO reactant energy level.The HOS(NO)O2-H2O can dissociate to the minor products,H2SO4 and HNO.The main products of the reaction of three gases NO2,H2O and HOSO are H2SO3 and trans-HONO.NH3 molecule plays a critical role to low the Gibbs free energy barrier due to making the acid more stable,so the final products of title reaction are NH4HSO3,NH4NO2,NH4HSO4 and HNO gases.The NH4+HSO3-ion pairs are formed with the four unites of H2SO3-NH3,as will NH4+HSO4-ion pairs were also investigated theoretically.In summary,controlling the emissions of combustion products containing nitrogen and sulfur is an urgent problem in the pollution area.