In order to develop a new energetic materials, nitrolysis of 3,5,9,11-tetraacetyl-14-oxo-1,3,5,7,9,11-hexaazapentacyclo［5.5.3. 0^2,6.0^4,10.0^8,12］pentadecane (Ⅰ) was studied in detail. Ⅰ was nitrolyzed selectively to 4-nitratomethyl-2,6,8,12-tetraacetyl- 10-nitro-2,4,6,8,10,12-hexaazaisowurtzitane (Ⅱ) with HNO3/Ac2O. While with mixture of nitric and sulfuric acids as nitration reagent, at 80 ℃ directly or at 15 ℃ 2 h firstly then 80 ℃ Ⅰ was nitrolyzed to CL-20 or 4-nitratomethyl-2,6,8,10,12-pentanitrohezaazaisowurtzitane (Ⅲ) respectively. Ⅱcan also be nitrated to Ⅲ. The structures of two new hexaazaisowurtzitane derivatives(Ⅱand Ⅲ) were confirmed by MS,IR,¹H NMR and ¹³C NMR.