Volatile oil was extracted from the rhizome of Cibotium barometz for the first time. Its content was determined to be 83.3 micrograms/g, decreasing significantly after the drug was processed. Twelve constituents from the volatile oil were identified by method of GC-MS. The main constituents were organic acids. The contents of palmitic acid and linoleic acid were the highest. After Cibotium barometz was processed, some constituents were found decreasing and some increasing.