Water extracts from Polygonum aviculare and Salix koreansis markedly inhibited the germination of lettuce and rice seeds, indicating the presence of biologically active substances. The biochemical substances such as salicylic and ＋ vanillic acid, tannic acid ＋ gallic acid, p-coumaric acid, p-cressol, sinapic acid and catechol etc. belonging to phenolic compounds were detected in the cultured cells, suggesting that the secondary metabolites can be synthesized in plant cell and tissue culture. In addition, fatty acid like linolenic acid and organic acid such as oxalic acid were presented in the highest amount, 3.7 ㎎/g and 14.288 ㎎/g, respectively, which seem to be related to exhibiting phytotoxicity of P. aviculare. Petroleum ether extract exhibited another potential relating to inhibitory effect which needs further investigation. Calli from two plant sources were easily introduced by uses of 1.0 ㎎/1 of 2.4-D and 0.1 to 0.2 ㎎/1 of BAP in MS basal medium which can be implemented for a large scale production through cell culture.