Scales excised from lily bulblets were cultured on MS medium supplemented with 0.044 or 4.4 μM BA in the dark for 180 days. The culture period was divided into stage 1 (day 0–30), stage 2 (day 31–90) and stage 3 (day 91–180). The scales were cultured at 25°C in stage 1, 25°C or 8°C in stage 2, and 25°C in stage 3. When the scales were cultured on medium with 4.4 μM BA at 25°C for 180 days, bulblets with and without an elongated stem were produced. The percentage of bulblets with elongated stems greatly increased when the scales had been cultured at 8°C in stage 2. On medium with 0.044 μM BA, only bulblets without elongated stems were produced. The diameter of shoot primodia significantly enlarged in bulblets produced on medium with 4.4 μM BA at 8°C in stage 2 and no such enlargement occurred under the other conditions. Nearly square parenchyma cells were observed in the non-elongated shoot primodia in the former bulblets but not in the latter. These cells changed into longitudinally rectangular ones in the internode of elongated stems. Procambium was arranged almost parallel to the shoot axis in the stem of bulblets in the medium with 4.4 μM BA, but not in the medium with 0.044 μM BA.