(±)-2-Amino-3-methylene pentanoic acid hydrochloride is a biologically active natural product，which was synthesized via Grignard reaction，oxidation，Grignard reaction，Wittig reaction etc unit reaction using serine as the raw material. Finally，the target compound was obtained in ten steps with an overall yield of 39%. The reaction conditions of oxidation，Grignard reaction and Wittig reaction were optimized. The improved process can be used to the synthesis of β-substituted vinylglycine analogues.