Tetraacetyldinitrohexaazaisowurtzitane (TADN),an intermediate in the preparation of CL-20,has been synthesized readily via the nitration of tetraacetylhexaazaisowurtzitane with HNO₃/AC₂O mixture. The TADN′s structure was determined by X-ray diffraction technique. Its crystal belongs to monoclinic,system and has space group P2₁/n with parameters: a＝1.12231(8) nm,b=1.41083(10) nm,c=1.12331(8) nm,Z=4,V=1.7395(2) nm³,d_c=1.628 g·cm^-3,β=102.039(2)°. The length of C(5)—C(6) bond is 0.1586 nm,a bit longer than that of normal sp³ C—C bond and shorter than the corresponding bond in CL-20. This is due to the fact that,in comparison with CL-20,the electron withdrawing effects of acetyl groups positioned in the two five-membered rings of TADN are weaker.