Three 5 mm strips excised from the basal region of young leaves of 6 Lilium species were cultured in vitro, and the rates of regeneration and the number of bulblets per explant were investigated. The bulblet productivity depended both on the kind of Lilium species and the origins of each explant. Growth regulators also affected the bulblet productivity; a-naphthaleneacetic acid (NAA) was absolutely required for the induction and growth of bulblets whereas addition of 6-benzyIaminopurine (BA) was ineffective.