Salt tolerance in Iris pseudacorus L. was tested whether it can be materialized to remove salt accumulation in water caused by nonpoint source pollution. Two groups of treatments were a nutritive salt group (NSG) of Hoagland solution of varying concentrations and a sodium salt group (SSG) of the solution of NaCl. In NSG leaf visible damages appeared in more than EC 5 mS·cm-1, while plants in SSG showed visible damage in all concentrations of NaCl. The damage symptoms were dark green in leaves and plant wilting in NSG, while browning of the leaf tips' browning in SSG. Plant biomass in NSG was highest in EC 1 mS·cm-1 the lowest in EC 9 mS·cm-1. In SSG, it was significantly decreased as salt concentration increased. Photosynthetic and root activities were reduced, and proline, a kind of stress-defense proteins, increased, accompanied with salt increase.