Using the young seedlings of nine leguminous species grown under upland and excessive moisture conditions for about two weeks, formation of the lysigeneous intercellular space in adventitious roots was investigated. Basal portions of the adventitious roots which were longer than 5 cm in length were fixed and stored in a solution of FAA. The materials were embedded in paraffin and cross sections 12μm thick were prepared. Under the upland condition, a lysigeneous intercellular space in the cortex of the adventitious roots was not clearly obseved in any leguminous species used. Under the excessive moisture condition, on the other hand, lysigeneous intercellular spaces in the cortex were clearly observed in soybean (Glycine max Merr.), wild soybean (G. soja Sieb. et Zucc.), adzuki bean (Vigna angularis Ohwi et Ohashi), black gram (V. mungo Hepper), mung bean (V. radiata R. Wilczek) and rice bean (V. umbellata Ohwi et Ohashi), while no lysigeneous intercellular space was observed in the hyacinth bean (Dolichos lablab L.), kidney bean (Phaseolous unlgaris L.) or cowpea (V. sinensis Endl.). Under the excessive moisture conditon, lysigeneous intercellular spaces were observed in all of the adventitious roots of soybean, black gram and rice bean plants. However, in wild soybean, adzuki bean and mung bean, some adventitious roots had lysigeneous intercellular spaces while some roots didn't.