The influence of bis(3-nitro-1,2,4-triazole-5-onato) lead(II) (Pb(NTO)₂), tetraaquo-bis(3- nitro-1,2,4-triazole-5-onato) copper(II) (Cu(NTO)₂) and tetraaquo-3-nitro-1,2,4-triazolato -5-onato copper(II) (Cu(NTO)) on the combustion characteristics and the thermal behavior of AP-CMDB propellants were experimentally studied. The results show that the thermal decomposition of NC and NG for the AP-CMDB propellants are affecteded obviously by the lead and copper salts of NTO, and the pressure exponents of the AP-CMDB propellants decreases obviously with the increase in burning rates of the propellants in the pressure range of 1~7 MPa and the decrease in the pressure range of 10~20 MPa. It is also found that Cu(NTO) has great effect on the combustion characteristics of the AP-CMDB propellant because the decompositions of both NC/NG and AP of the propellant are obviously promoted by Cu(NTO).