The influences of pressure on thermal decompositioncharacteristics of N-oxidiation-3,3′-azobis (6-diamino-1,2,4,5-tetrazine)(DAATO_3.5) were investigated by high pressure differential scanningcalorimetry (PDSC) and thermogravimetryderivativethermogravimetry (TG-DTG). The results show that the thermal decompositioncharacteristics of DAATO_3.5 is sensitive to pressure. DAATO_3.5has an intense exothermic decomposition process in the temperaturerange of 240-257℃with a sharp exothermic peak at 250℃and the exothermic quantity of DAATO_3.5 is 3088J·g^-1 under 0.1MPa. The thermal decomposition peaktemperature of DAATO_3.5 is obviously reduced to 240.5℃at 3MPa and continues slightly to reduce with the increase of thepressure. The exothermic quantity of DAATO_3.5 is increased tomaximum at 5MPa then decreased with the increase of the pressure. It was foundfrom the comparision of ΔT at different pressures thatpressure had no significant effect on the decomposition temperature range ofDAATO_3.5.