A complex from copper(II) perchlorate with 4-amino-1,2,4-triazole (4-AT, C(2)H(4)N(4)) was synthesized, and elemental composition, molecular structure, and explosive properties were determined. To this end, elemental and X-ray analyses were carried out, sensitivity to mechanical and thermal stimuli was measured, mechanism of thermal decomposition was investigated, and kinetic parameters of decomposition were determined. In the next step measurements of heat of combustion and detonation velocity were performed. Detonation parameters were also calculated. It was stated that the complex has slightly distorted square bipyramidal (4 + 2) coordination. The four basal bonds are formed by nitrogen atoms of four 4-AT molecules. The coordination of the metal is completed by two axial oxygen atoms, one of the perchlorate ion, and one of the water molecule. With respect to explosive properties, tetrakis(4-AT)copper(11) perchlorate monohydrate belongs to the group of sensitive secondary explosives.