To clarify the reed (Phragmites australis) stand\'s effects on the sediment properties and its increasing
pattern, breaths of reed stands in 1999 and 2000, and sediment properties - water, salt, organic matter, sulphur,
nitrogen, carbon and hydrogen contents - along th depth at the three stands in 2007 were surveyed at Suncheon
Bay. Regardless of reed stand, the more distance from the land was long, the more water and salt contents of
sediment were high. Organic matter content of sediment was high and increased with the reed biomass at the upper
layer but low regardless of biomass at the lower layer. Sulphur content of sediment was higher at old reed stand
(0.33%) than at new stand (0.21%) or non-vegetated stand (0.23%). Carbon, nitrogen and hydrogen contents of
sediment were similar at three stands in mean values. However, their contents were high at upper layer and low at
lower layer in a stand. Therefore, the changing pattern of organic matter content with the depth was similar to but
not coincided to the inorganic nutrients\' ones. The mean breadth of reed stands increased 2.33±0.73 m in 1999 and
3.65±1.64 m in 2000. However, the increase of reed stands\' breadth a year varied along the direction, year or
stands, so that there was not a trend in increasing pattern. It was thought that this increasing pattern made the
reed\'s patch round. The height and density of reed shoot in newly formed stand decreased with the distance from
the center of stand. In the newly formed peripheral area of a reed stand, the shoot density was not related with the
land (north) or sea (south) direction, however, the shoot height was higher in the sea (south) than in the land
(north) direction.