The thermal properties and reliability of the stearic acid (SA) with acetamide (AC) binary mixture were characterized using differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR). The phase diagrams for the SA-AC binary mixture with AC in the metastable and the stable form were constructed. The eutectic system with stable AC is 0.604 mol fraction SA, and displayed a melting temperature (T-m) of 64.55 degrees C and latent heat of melting (Delta H-m) of 193.87J.g(-)1. The eutectic systems with metastable AC are 0.397 and 0.604 mol fraction SA. The melting temperatures are 62.23 degrees C and 62.54 degrees C, and latent heats of fusion are 222.10 J.g(-1) and 194.28J.g(-1), respectively. Following accelerated thermal cycling tests, TG and FTIR analysis indicate that the eutectic mixture (chi(sA) = 0.397) with the metastable AC has good cyclic and thermal stability. The results show that the SA-AC eutectic mixture use as phase change material (PCM) possess good prospect for low temperature thermal energy storage (TES) applications. (C) 2016 Elsevier Ltd.