Twelve of the alkylcarboxybetaine derivatives such as 2-(trimethylammonio)dodecanvate, 2-(trimethylammonio) tetadecanoate, 2-(trimethylammonio)hexadecanoate, (dimethyldodecylammonio)ethanoate, (dimethyltetradecylammonio)ethanoate, (dimethylhexadecylammonio)ethanoate, 2-( dimethyltetradecylammonio)propanoate, 2-(dimethyltetradecylammonio)propanoate, 2-(dimethylhexadecylammonio)propanoate, 2-(dimethyldodecylammoino)-3-phenylpropanoate, 2-(dimethylhexadecylammonio)-3-phenylpropanoate have been synthesized from the 2-baomoalkanoic acid, trimethylamine, dimethylalkylamine, alanine and phenylalanine, respectively. These reaction products have been separated by ion-exchangechromotography and detected by paper chromotography, elementary analysis and infrared spectroscopy.