Young leaves of 2-year-old true laurel [ Cinnamomum porrectum (Roxb.) Kosterm.] (Figure 1) were collected from greenhouse of Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand and used as explants for callus induction. Surface sterilization Leaf explants were cleaned repetitively with 5% (v/v) detergent solution Teepol for 5 minutes and washed with running tap water for 15 minutes to eliminate unwanted matter. After that, they were soaked in 70% (v/v) ethanol for 1 minutes and surface sterilized with 15% (v/v) Chlorox for 15 minutes. After soaking with sterile distilled water 3 times each for 5 minutes, explants (leaf blade with midrib) were cut into 1 X 1 cm2 before transferred to the induction medium.