Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory (DFT) method at the B3LYP/6-311++G** level. The maximum intermolecular interaction energy is –35.42 kJ/mol via the basis set superposition error-correction (BSSE) and zero point energy-correction (ZPE). Charge transfers between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds’ strength rather than their number. The dimerization processes of Ⅳ ,Ⅴ and Ⅵ can occur spontaneously at 200 K. Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory (DFT) method at the B3LYP / 6-311 ++ G ** level. The maximum intermolecular interaction energy is -35.42 kJ / mol via the basis set superposition error-correction (BSSE) and zero point energy-correction (ZPE). Charges between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds’ strength rather than their number. The dimerization processes of Ⅳ, Ⅴ and Ⅵ can occur spontaneously at 200 K.