In this paper we analyze literature values of the Henry's law constants of peroxyacetyl nitrate (CH3C(O)O2NO2, PAN) and peroxynitric acid (HO2NO2) in water and liquid sulfuric acid, and derive correlative expressions to predict the solubilities of PAN and HO2NO2 in liquid H2SO4 over a wide range of temperature and acidic composition. To a first-order approximation, the results indicate that the Henry's law constants (in units of mol kg-1 atm-1) are ln(H)=1.07-mH2 SO4¿(0.69-152/T)-5810¿(1/T0-1/T) for PAN and ln(H)=3.69-mH2 SO4¿(-0.25+65/T)-8400¿(1/T0-1/T) for HO2NO2 where mH2SO4 is the molality of sulfuric acid, T is the temperature of solutions, and T0=298.15 K. The activity coefficients of PAN and HO2NO2 in aqueous H2SO4 are found to have a simple relationship with the molality of H2SO4. ¿ 1999 American Geophysical Union