N-Methyl-N-(2-nitroxyethyl)nitramine (Me-NENA),N-ethyl-N-(2-nitroxyethyl)nitramine (Et-NENA) and N-butyl-N-(2-nitroxyethyl)nitramine (Bu-NENA) were prepared by the reactions of methyl ethanolamine,ethyl ethanolamine,butyl ethanolamine and nitric acid,acetic anhydride respectively. The structure of the target products were identified by ¹H NMR,IR and elemental analysis. The parameters affecting the yield and purity of Et-NENA,such as temperature,reaction time,nitric acid and acetic anhydride were discussed. The optimum conditions were given: n(ethyl ethanolamine)：n(nitric acid)：n(acetic anhydride)=1：2.6：2.4,the reaction temperature of the first stage 5-10 ℃,the second reaction temperature 40-45 ℃,reaction time 15 min,yield of Et-NENA was over 84.70% and the purity of the refined product was over 98.07%. The physical,chemical,safety properties and thermol decomposition of alkyl-NENAs have been experimentally studied.