Thuja occidentalis Linn. (Family cupressaceae), commonly known as American Arbore Vitae, is an evergreen tree and native of North America. Leaves & twigs, which contains essential oil, condylomatous growth, spongy tumours, warts, ill effects of vaccination etc. Twigs fan-shaped; leaves ovate, obtuse, having resin ducts & parenchymatous mesophyll; stem shows resins ducts in parenchymatous cortex and alternate bands of phloem parenchyma & phloem fibres. TLC of alcoholic extract in chloroform: Methanol (9:1) shows 8 spots under UV light, and UV absorbance shows peak at 260nm.