This article w as the fi rst repot r of the v aria tion of leaf tissue microst ructure o f "Baojiao 83- 5029" so ybean a nd "Ke 8118" soybea n under w ater- log ged st ress, With the increase o f wa ter- lo gg ed intensity "Bao jiao 83- 5029" performed w ater- toleranceg radually and leaves colo r turned into g reen. The amount of peroxisome, mi tocho ndrion, chlo ro plast increased and their activa tio n became st ro ng , and leav es became plump.On the o ther hand, the w ater- ubto lerante "Ke 8118" was fai rly w eak, leav es becamew ilt a nd etio lated. Mitocho ndrio ns started to swell , thei r cri stacs di sappeared and preformedto be empty , and the membrame of chloro plast w as brokan by the giqantic sta rchg rains.