Taking moderately stronger flood tolerant melon ‘Cuixi’ and relatively weaker flood tolerant
melon‘ Shijimi’ as materials，this paper studied the effects of half submerged and total submerged（1，3 days）
stress and stress relieve（1，3，5 days）on respiration and other physiological metabolism of melon seedlings．
The results indicated that comparing with the contrast carrying out normal water management，waterlogging
stress decreased the fresh weight，dry weight and activities of melon seedlings root system，and the inhibiting
effect of total submerge treatment was more significant．Waterlogging stress increased the activities of lactate
dehydrogenase（LDH）and alcohol dehydrogenase（ADH），reduced the activities of malate dehydrogenase
（MDH）and succinate dehydrogenase（SDH）．The reducing scale of ‘Shijimi’ with relatively weaker flood
tolerance was larger than that of ‘Cuixi’ with moderately stronger flood tolerance．The activities of superoxid
dismutase（SOD），peroxidase（POD）and catalase（CAT）of these 2 varieties showed an increasing tendency
after waterlogging stress．Therefore，waterlogging stress inhibited the aerobic respiration of melon seedlings，
while accelerated the anaerobic respiration metabolism，eventually leading to restrain the root system growth．
Moreover，the inhibition rate suffered by‘ Shijimi’ was larger than that of‘ Cuixi’．