The objective of this study is to obtain information about the thermal decomposition behaviors of hydrazine (N2H4) caused by metals, using differential scanning calorimeter (DSC) and SuperCRC. The DSC measurements revealed that the exothermic reactions of N2H4 were caused by the reaction conditions such as the type of cells; the T-DSC with a gold pan is 485.2 K and that with a glass capillary is 620.5 K. Besides, the activation energy of the thermal decomposition of N2H4, calculated from the Kissinger and Ozawa methods, were found to be about 38 +/- 2 kJ mol(-1) in the gold pan and 141 +/- 8 kJ mol(-1) in the glass capillary. Moreover, a heat flow profile was observed with SuperCRC during the mixing of N2H4 and the metal ion solution at 298 K. The maximum heat flow was related to the metal ion oxidative characters. The higher oxidative characters would provide a faster acceleration for the exothermic behavior than the lower oxidative ions. Based on this study, Mn(VII) and Cr(VI) were considered to exhibit strongly oxidative characteristics during mixing with N2H4. (C) 2005 Elsevier Ltd. All rights reserved.