Heat capacities of the water + lithium chloride + lithium nitrate (salt mole ratio 2.8:1) system were measured in the range of temperatures from 283.15 to 433.15 K and in the range of absorbent concentrations from 9.1 to 63.5 mass%. The measurements of heat capacity were made with two separate experimental apparatus for individual temperatures below 343.15 K and above 353.15 K. An empirical formula for this ternary system was obtained as a function of absolute temperature by a least-squares method from these experimental data. Maximum and average absolute deviations between these experimental data measured with two apparatus and the calculated values from this empirical formula were 0.97% and 0.35%, respectively.