Effect of 2,4-Dbutylate treatment of soil on emergence rate, plant height, stem diameter, freshweight, leaf length and width of three main cultivars in Heilongjiang Province, Dongnong 52, Hefeng 55 and Heihe 48, was studied in the paper by pot-cultured experiment. The results indicated that when the application rate was 540 g/hm², only leaf length and width of true leaf of these three soybean cultivars and fresh weights of Heihe 48 re-duced. If we take the fresh weight as the only evaluating indicator, Heihe 48 was more sensitive than the other twocultivars; When the application rate was 1080 g/hm²,emergence rates were normal, but stem bases expanded andplant heights, fresh weights and leaf lengths and widths all reduced. Yield of the most sensitive cultivar Heihe 48 de-creased. When the application rate reached or exceeded 1620 g/hm², emergence rates of three soybean cultivars re-duced significantly. Yield of Dongnong 52 and Heihe 48 reduced. When the application rate reached 2160 g/hm²,emergence rates of three soybean cultivars were too low, and leaf lengths and widths were inhibited for too long, thusyield of all three cultivars reduced.