To evaluate the thermal stability of 1-amino-2-nitroguanidine(ANQ) and investigate the potential application value of ANQ as energetic material, thermal behaviors, specific heat capacity and adiabatic time-to-explosion of ANQ were studied by DSC, micro-DSC and TG/DTG methods. Results show that thermal behavior of ANQ can be divided into two coterminous intense exothermic decomposition processes. The peak temperatures of the two decomposition processes at the heating rate of 5 ℃·min^-1 are 192.5 ℃ and 196.2 ℃, respectively, and the whole decomposition enthalpy is -2075 J·g^-1. The apparent activation energy and pre-exponential constant of the first decomposition process are 224.3 kJ·mol^-1 and 10^23.15 s^-1, respectively. The self-accelerating decomposition temperature and critical temperature of thermal explosion for ANQ are 184.5 ℃ and 192.7 ℃, respectively. The molar heat capacity of ANQ is 145.5 J·mol^-1·K^-1 at 298.15 K. Adiabatic time-to-explosion was estimated to be about 60 s. The thermal stability of ANQ is good.