Abstract: For improving the mechanical and combustion properties of BAMO-THF/PSAN propellant, azodicarbonamide(ADA) which is a kind of foaming agents was added into the propellant. Effects of ADA on the properties of BAMO-THF/PSAN propellant were studied by FTIR, TG, tensile and burning rate test, and the mechanism was discussed. It was shown that ADA has improved the mechanical and combustion properties of BAMO-THF/PSAN propellant. When the mass fraction of ADA was 8%, the maximum stress increased by about 40%, the elongation at maximum stress increased by about 36%, reaching the maximum, and the pressure exponent fell to 0.56 from 0.72, while the specific impulse declined just 2.1%.