Nowadays, many of synthetic compounds with potent and diverse biological activity have been prepared from available natural compounds, which are safe, inexpensive and readily available. Propolis is a resinous bee-hive product containing bee secretions and plant resins, popular as a health supplement because of its various biological properties, and composed primarily of artepillin C, a prenylated derivative of cinnamic acid. The hydro-distilled volatile oil of the Cinnamomum burmannii bark was analysed by using gas chromatograph – mass spectrometer (GC-MS). It was rich of phenylpropanoid compounds with cinnamaldehyde as the major compounds. Prenylation of the essential oil was succesfully carried out by using 3,3-dimethyl allyl bromide with heterogeneous catalyst, and the products were identified by GC-MS. Prenylated essential oil showed high antioxidant activities which are suggested due to prenylated cinnamaldehyde, since it is the main compound.