A new synthetic route of nitroform (NF), the crucial raw material of hydrazinium nitroformate (HNF), was presented in this paper: Preparation of NF with a series of a methyl carbonyl compounds as substrates was investigated by utilizing fuming HNO3 (98%, white) as the nitrating system. The results indicated that acetylacetone showed a good efficiency for the further studied reaction. The influence of various factors, such as additives, reaction temperature, time, and the molar ratio of-fuming nitric acid to acetic anhydride, on the yield of the NF was demonstrated. NF was obtained under optimized conditions with a good yield of 40.8%. The reaction mechanism, which involved nitration-hydrolysis-nitration-hydrolysis, was proposed and verified by the C-13 NMR tracking. Acetylacetone displays excellent prospects for industrial production of NF, because of the use of inexpensive raw materials, mild conditions, and a satisfactory yield of NF.