The ternary phase equilibrium for 1-(3-nitrophenyl)ethanone and 1-(4-nitrophenyl)ethanone in methanol or n-propanol were determined at 298.15, 308.15 K and 318.15 K under atmospheric pressure in this work. Based on the measured mutual solubility data, the isothermal ternary phase diagrams were constructed. In each ternary phase diagram, there were one co-saturated point, two boundary curves, and three crystalline regions. The crystallization region of 1-(3-nitrophenyl)ethanone was about the same as 1-(4-nitrophenyl)ethanone at all researched temperatures. The NRTL model was used to correlate the solubility of the ternary 1-(3-nitrophenyl)ethanone + 1-(4-nitrophenyl)ethanone + solvents. The correlation results were evaluated by the values of relative average deviation (RAD) and root-mean-square deviation (RMSD), and their values were 4.18 x 10(-2) and 3.60 x 10(-3), respectively. The calculated results via this model were all acceptable for ternary solid-liquid phase equilibrium. The ternary phase diagram obtained will play an important part in separating the mixture of 1-(3-nitrophenyl)ethanone and 1-(4-nitrophenyl)ethanone. (C) 2019 Elsevier Ltd.