By means of Gaussian 98 packages software at the level of B3LYP/6-31G,the structure of tetraacetylhexaazaisowurtzitane(TAIW) was optimized and calculated. The theoretical analysis of the structure of TAIW,such as bond length,bond angle,dihedral angle and charge was performed. Judging from the analysis,the amine in the hexa-ring is active. And the solvent-effect on TAIW′s stabilization is large. Moreover,the calculated and the experimental IR harmonic frequenceies,intensities of TAIW are listed,and the relative-error of harmonic frequenceies is less than 4%.