To provide a method for profitably producing an aminopolycarboxylic acid having an excellent chelating ability or its salt from an inexpensive raw material in a high purity in a high yield and at a low cost.

This method for producing an amino carboxylic acid or its salt expressed by formula II (R is a 1-21C alkyl group or an alkenyl group; M is H, an alkali metal, an alkaline earth metal, ammonium or a basic amino acid) comprises subjecting an aminoalcohol derivative of formula I to an oxidative dehydrogenation reaction in the presence of an alkali metal hydroxide, water and a copper-containing catalyst.