β-asarone (cis-isomer of 2, 4, 5-trimethoxy-l-propenylbenzene) is a constituent of oil derived from the dried rhizome of A. calamus which is used as herbal medicine. Ethyl acetate extract was prepared from fresh leaves of acorus calamus. The extract was separated in silica gel column chromatography until single spot of beta asarone was observed on TLC. The pure fraction analyzed in NMR spectroscopy. 1H-NMR and 13C-NMR were recorded on a Bruker 400 MHz NMR spectrometer at 298K. Spectral assignments of fraction were correlated with standard beta asarone. The comparison confirmed pure beta asarone in the fraction.