The thermal conductivity of ammonium sulfate + water, ammonium nitrate + water, and ammonium sulfate + ammonium nitrate + water is of great significance in the national defense industry and military engineering for manufacturing of various energetic chemicals. The measurements, covering a temperature range from (278.15 to 333.15) K, have been performed by a transient hot-wire technique over a wide range of concentrations. The densities of ternary aqueous solutions of ammonium sulfate + ammonium nitrate are also presented at the same temperature covering different portions of ammonium sulfate and ammonium nitrate. The thermal conductivities of binary aqueous solutions of ammonium salts are correlated by polynomial functions in terms of temperature and weight fraction for the purpose of interpolation. The Aseyev equation in terms of weight fraction is also used to represent the thermal conductivities of ternary mixtures of these compounds. The ideal mixing rule of Young has been successfully applied to correlate the ternary densities of aqueous ammonium sulfate + ammonium nitrate solutions based on relevant binary solution properties. The agreement between the correlation and the experimental data is pretty good.