Exogenously supplied ascorbic acid (AsA) strongly induced furanocoumarin production in leaf and root cultures of GLEHNIA LITTORALIS, but not in cell suspension cultures, after 24 h of treatment. The dose dependency showed that both organ tissues responded well to AsA supplied at concentrations of 10 - 40 mM. For induction of furanocoumarin production, roots required contact with AsA for at least 6 h and productivity markedly increased after 8 h of treatment. This is the first report of the induction of furanocoumarin biosynthesis by AsA alone and of the detection of furanocoumarin biosynthesis in a root culture system.