After 50 days long-day maintenance of D. lavandulifolium, seedlings with 6 leaves had different flower bud under different photoperiodic induction during 30 days treatment. The result showed that maximum flower bud (70%) was observed in 12hr light/ 12hr dark and 13hr light/11hr dark after 30 days induction. 11h light/13h dark also showed good flower bud (60%). 30% flowering were observed on 9hr light. None flower bud was observed in control plant. The earliest bud appeared only need 10 days after short-day induction.