Abstract: The experiments of fumigation of soybean were carried out in 4 sets of open top field chamber.The HF concentrations within the four cambers, A, B, C and D ( CK ) 0.0036, 0.011, were 0.038 and 0.0007 mg/m³ respectively.The results showed that the changes in the leave electric conductivity were closely correlated with the environmental condition in which the leaves grew and absorbed fluoride and with the developing stages of soybean plant.It was found that the fluoride content and absorbtive rate of leaves were increased aynchronously with the increment of time and concetration of fumigation,the maximum value appeared in the treatment of C group which had higher HF concentration.Much more fluoride was accumulated in leaves than in other parts of the plant, the differences in fluoride content of leaves among all treatments were significant, but that between root, pod-skin and bean was not obvious.Fumigation with higher concentrations caused obvious varietions in the number ot pod, bean as well as in the bean weight, When the concentration exceeded 0.0039 nig/m8, the yield of soybean would probably decrease to n large extent.