Abstract:Leaf-spraying fulvic acid can obviously enhance the watermaintaining capacity of wheat seedlings, especially when under the condition of drought stress. The major physiological influences by fulvic acid are: decrease in leaf transpiration, increase in diffusion resistance of stoma and increasing in dry matters in the seedlings. Fulvic acid can also cause the proline content in the leaves to increase twice as much as that in the controls, and even in the condition of sufficent water supply,the poline content in the treated leaves increased by 78%.