X-ray diffraction （XRD）, differential scanning calorimeter （DSC） and impact sensitivity instrument were used to characterize the properties of 1-Methyl-4, 5-dinitroimidazole （MDNI）. Furthermore, specific heat capacity, thermal kinetic parameters, thermal decomposition reaction rate constant, critical explosion temperature and the drop height for impact initiation of MDNI were calculated and analyzed. The results show that MDNI is well-crystallized. The melting point of MDNI is about 74 ℃, and the specific heat capacity of MDNI is 9. 314 4 J/（g · K） and 10. 596 0 J/（g · K） when the temperature is 60 ℃ and 90 ℃, respectively. The apparent activation energy and pre-exponential factor of MDNI are calculated as 81.62 kJ/mol and 6. 78×10^7 s^-1 , respectively. The relationship between thermal decomposition reaction rate constant of MDNI and temperature is logk=7.83-4268.11/T. The critical temperature of MDNI thermal explosion is 234. 86℃. The drop height for impact initiation of MDNI is 95.3 cm.
