Abstract: The chemical composition of the essential oil of Platycladus orientalis and its resistance to termite were studied.The results showed that:(1) The content of the essential oil was high.The essential oil with fragrant smell had resistance to both termite and mite and could refresh the air.(2)Thirty eight components were identified in the essential oil. (3)The ethanol extractive of the tree species had absorption on the wavelength (268±2) nm and (411±2) nm of UV,which could identify the tree species.