A new 8,1 -neolignan, tatarinone, 4-[2-(1,2,3-trimethoxybenz-5-yl)-1-methylethyl]-2,5- dimethoxy-4-(2-propenyl)-2,5-cyclohexadien-1-one, has been isolated from Acorus tatarinowii rhizome and its structure determined by spectroscopic methods, including 2D-NMR spectra. Asarylaldehyde and a mixture of -asarone and -asarone were also isolated and indentified.