As a new azide-free gas generating pyrotechnic composition, the performance of four kinds of 5-aminotetrazole nitrate (5-ATN) gas generating compositions were investigated by hygroscopicity, compatibility, impact sensitivity, heat of combustion and burning temperature measurement. The advantages of the gas generant using KNO₃ as an oxidizing agent include small hygroscopicity, better compatibility, lower impact sensitivity and proper burning temperature. The degree of water sorption in the mixed system with Sr (NO₃)₂ was much higher than that with KNO₃. The participation of CuO can reduce the hygroscopicity of the system with Sr (NO₃)₂. As the oxidizing agent and catalyst, CuO can also decrease the impact sensitivity, heat of combustion and burning temperature of both systems. 5-ATN gas generant provides fair compatibility using 5-ATN as separate system.