Geometrical structures of furoxan monomer and dimers were optimized at the B3LYP/6-31++G^** level. It is found that the planar structure of sub molecule is not changed in the process of forming a dimer. Based on the frequency vibration results,it can be speculated that the π-π conjugation in the structure has influence on the C—H stretching. Consequently,the C—H stretching exhibits some red shifts and its intensity is strengthened. The ²ρ at bond critical points(BCP) of C—H bonds are negative,contrary to those of O…H and N…H hydrogen bonds. It indicates that the O…H and N…H hydrogen bonds (HB) are accord with the common HB features. The capability of the dimers to concentrate electrons at BCP of C—H bonds enhanced. The recently developed aymptotically corrected symmetry-adapted perturbation theory,combined with density functional theory,was used to study the contributions of intermolecular interaction energy of furoxan as a simple model. The electrostatic energies of dimer Ⅰ and dimer Ⅱ are -30.10 kJ·mol^－１ and -37.36 kJ·mol^－１ respectively,which are equal to the total energies. It directly reflects that the HB interaction of furoxan is dominated by electrostatic energy.