The present invention provides N-alkylaspartyl dipeptideester compounds and salts thereof, such as N-[N-[3-(3-hydroxy-4-methoxyphenyl)-3-methylbutyl]-L-.alpha.-aspartyl]-L-- phenylalanine 1-methyl ester, which provide high degrees of sweetness in comparison to conventional products, compositions and products containing the novel aspartyl dipeptide ester compounds and method of producing the novel aspartyl dipeptide ester compounds.