Abstract: By using a precision automatic adiabatic calorimeter the heat capacity of hydrazine nitrate in the temperature range of 220-370 K have been measured. The heat of fusion, melting point and entropy of fusion for the sample have been obtained from the results of heat capcity measurements. The precision of heat capacity measurements for hydrazine nitrate is ±0.2％, as shown by the root-mean-square (r. m. s.) of the percentage deviation, and the relative error for heat of fusion measurement is 0.1％. In order to varify the reliability for all of these measurements we have determined the heat capacity, heat of fusion as well as the melting point of pure ice with the same apparatu and the results were found to be in agreement with the data in literature. Then, the heat of fusion and melting point of hydrazine nitrate have been measured with the SETARAM high temperature calorimeter. The results obtained by the two apparatuses coincided with each other. Besides, the purity derived from the heat capacity measurements of the sample is in agreement with the results from chemical analysis. The facts show that the data from calorimetric measurements for hydrazine nitrate are reliable.