PROBLEM TO BE SOLVED: To create an artificial reed field in a brackish water region through planting reeds so as not to wither up even if affected by the salinity of the brackish water region.SOLUTION: The artificial reed field B is created through the following steps: setting a brackish water zone A as a planned area where an artificial reed field B is to be created by building a water permeable bank 11 such as a stone mound 11a； putting planting soil 12 for reeds into the inside of the bank 11 up to a ground height preset to a level higher than the mean sea level so that the salinity in pore water contained in soil becomes 14 PSU or less in terms of practical salinity； and planting the root of the reeds in the thus prepared planting soil 12.
