The thermal decomposition process was studied by the TG-DTA analyzer. The results show that the decomposition process of sodiumhydroxyethyl sulfonate consisted of three stages: the mass loss for the first, the second and third stages may be about the groups of CH3CH2OH, CH3CHO and SO2 volatilized, respectively. The decomposition residuum of three stages was analyzed by FT-IR, and the results of FT-IR agreed with the decomposition process predicted by theoretical weight loss. The specific heat capacity of sodiumhydroxyethyl sulfonate was determined by differential scanning calorimetry (DSC). The melting temperature and melting enthalpy were obtained to be 465.41 K and 25.69 kJ . mol(-1), respectively. The molar specific heat capacity of sodium hydroxyethyl sulfonate was determinated from 310.15 K to 365.15 K and expressed as a function of temperature. (C) 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.