Chemical research showed that drug Acori contain volatile oil, and that the quality of volatile oil (0.53% ~ 2.l5 % )is different based on the drug's origin. The volatile oil mainly contain β-asarone, a-asarone, r-asarone, methyleugenol,methylchavicol, dehyde, eugenol, cis-/trans-methylisoeugenol, safrole etc. The main constituents of volatile oi1 from defferemt localities or different species of Acorus are different. Pharmacological studies indicated that drug Acori have the functions as beow: l). To control epilepsg; 2). To Prevent muscatine; 3). Anticancer; and 4). For mutagenicity and careinogenicity.