The main objective of this study is a trial to investigate the efficiency of cinnamomum zeylanicum (cinnamon) oil against paracetamol induced hepatotoxicity in male rats. The bark cinnamon was hydrodistilled using Clevenger,s apparatus to yield essential oil 2.3%.Total phenolic compounds and scavenging radical effect on 2, 2-diphenylpicrylhydrazyl (DPPH) were investigated. Gas chromatographic- mass spectroscopy fractionated cinnamon bark volatile oil to six components accounting for 100% of total amount. Cinnamaldehyde was found as the major component 68.01% followed by Eugenol 11.47, Cinnamyl alcohol 6.52% , α- murolene 5.24%, δ- cadinen 4.41% and Methyl eugenol 4.35%. Biological experiment was carried out for eight weeks. Results revealed that liver marker enzymes alanine transaminase (ALT) aspartate transaminase (AST), alkaline phosphatase (ALP) were increased. On the other hand serum total protein and serum albumin were decreased as well as, lipid profile of total lipids (TL), triglycerides (TAG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) were increased and high density lipoprotein cholesterol (HDL-C)was decreased in paracetamol treated rats(group2). Lipid peroxidation malondialdehyde (MDA) was increased in liver tissue of rats treated with paracetamol, while activities of glutathione peroxidase (Gpx) and Glutathione-S-transferase (GST) were decreased. Cinnamon oil both dose and silymarin showed remarkable hepatoprotective and antioxidant activity against paracetamol induced hepatotoxicity as judged from the serum marker enzymes and antioxidant in liver tissue.