A process for producing &agr;-amino-dihalogenated methyl ketone derivatives by reacting an N-protected &agr;-amino acid ester with a dihalomethyl lithium is provided. This process is suitable for the production on an industrial scale and by this process, &agr;-amino-dihalogenated methyl ketone derivatives and &bgr;-amino-&agr;-hydroxycarboxylic acid derivatives can be obtained efficiently and economically advantageously.