Abstract: Technology for the preparation of ammonium cerium (Ⅳ) nitrate with bastnasite as the main raw material was studied.Preparation process can be described as follows:nitric acid solution of Ce (Ⅳ) can be obtained by steps,such as bastinazite roasting,dilute sulphuric acid leaching,extractant-selective extraction of cerium,reextraction of using nitric acid to transport Ce (Ⅳ) from organic phase to water phase.Then,high-purity product of ammonium cerium  (Ⅳ) nitrate can be produced through the reaction of adding ammonium nitrate powder into cerium nitrate solution.The effects of preparation conditions,such as roasting temperature,leaching and selective extracting factors,and reaction time on the purity of synthesized ammonium cerium (Ⅳ) nitrate as well as the impact of this technology on the environment were discussed.The purity of prepared ammonium cerium (Ⅳ) nitrate with this technology was larger than 99％ and the yield was more than 85％.