We investigated the chemical constituents of the fibrous root of Ophiopogon japonicus and their cytotoxicities against Hela and Hep2 cells.Ten compounds were purified by various chromatographic techniques.Their structures were identified as 2 - hydroxylophiopogonone A（1）,5,8-dimethoxy-6-methyl-7-hydroxy-3-（2 -hydroxy-4 -methoxybenzyl） chroman-4-one（2）,5,7- dihydroxy-6,8-dimethyl-3-（4 -hydroxybenzyl） chroman-4-one（3）,7,4 -dihydroxy-5-methoxyflavanone（4）,N-trans-coumaroyltyramine （5）,N-trans-coumaroyloctopamine（6）, N-trans-feruloyltyramine （7）, 4-hydroxycinnamic acid （8）, caffeic acid （9）, and ferulic acid （10） on the basis of spectroscopic analyses. Compounds 4, 6, 7, 9, 10 were obtained from this genus for the first time. The cytotoxic activities of 1, 2, 4, 5, 6, 7, 9 and 10 against Hela and Hep2 cells are described.
