Sowing time of soybean (Glycine max [L.] Merr.) often coincides with the early onset of rainy season. Germinating seedsencounter a transient to prolonged period of water-logging that causes anoxia (absence of oxygen) and hypoxia (insufficientoxygen) resulting in poor germination. This reduces crop stability and yield. One of the factors responsible for flood tolerance isactivity of alcohol dehydrogenase (ADH) during flood. The effect of ADH activity during flooding and difference in floodtolerance level were investigated using two soybean cultivars, Peking and Tamahomare, and their F9 recombinant inbred lines(RILs). Tamahomare showed higher ADH activity than Peking. There was a great variation in ADH activity among the RILs.QTL analysis detected five QTLs for ADH activity (qAas1-5) on five linkage groups, LG_A2, D1a, F, K and L. The QTL qAas4was close to a QTL for shoot damage and conductivity of germinating seeds after flooding treatment.