PURPOSE:To obtain theanine with industrial advantage while reducing the content of caffeine or tannin by carrying out cell culture of tea using a basal medium containing ethylamine and derivatives thereof. CONSTITUTION:A slice of stem of tea sprout is subjected to tissue culture in a basal medium containing 1-250 mM ethylamine, derivatives thereof (single substance such as ethylamine hydrogenchloride or ethylamine hydrogensulfate or mixture thereof), an ammonical nitrogen and a nitrate nitrogen in an amount larger than that of the ammoniacal nitrogen as N source under illumination at 10-32 deg.C so as to induce callus. The resultant callus is subjected to subculture in the above-mentioned basal medium (MS-TEA medium) and to further subculture under dark. The subcultured callus is then subjected to shake culture under dark in the above mentioned basal medium, thus giving the objective theanine.
