PROBLEM TO BE SOLVED: To create an artificial ditch reed field in a brackish water zone through planting ditch reeds so as not to wither up even if affected by the salinity of the brackish water in a ditch reed field. SOLUTION: This artificial ditch reed field B is created through the following steps: making a brackish water zone (A) in a predetermined area where an artificial ditch 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 ditch 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 in terms of practical salinity, and planting ditch reed stocks in the thus prepared planting soil 12.
