Abstract: Effect of seed germination and growth of some crops and weeds by extract of wheat was studied during 1990～1994. The results showed that the germ ination of Amaranthus retroflexus treated with wheat extract (500m g/kg) was induced by 86% and the height and dry weight of the same species treated with the extract (100m g/m² ) in soil were induced by 78% and 82%. Field test showed that Stella riamedia (L. ) plant was killed by extract (100m g/m²) from wheat extract.