Decomposed liquids from soybean stubs(SSDL)on the germination and growth of soybean were instigated by solution-culture experiments and chemical analysis indoors.The results showed:SSDL inhibited the germination of soybean seeds,reduced the soybean roots activities and soybean plant resistance which embody in dropping of alpha-naphthylamine oxidase and the active uptake area of soybean roots.At the same time,SSDL demaged the structure of biomembranes which can increas of the leave's relative electric conductivity.