Abstract: In order to study the hydrostatic settling of suspended matter of large shallow lake,Four experiments,based on the Taihu lake,were conducted in the laboratory for hydrostatic settling behavior of suspended matter in Taihu lake in April and May,2005.The settling velocity of suspended matter was calculated by McLaughlin method.The results show that the settling velocity of particular inorganic matter(PIM) is the biggest,and the second biggest one is that of suspended matter (SS),the smallest one is that of particular organic matter(POM).During the same time of settling,the settling velocity of PIM is 1.6-2.0 times bigger than that of SS,the settling velocity of POM is 0.3-0.7 times bigger than that of SS,and the settling velocity of PIM is 2.5-5.5 times bigger than that of POM.The results also show that the suspended matter concentration decays exponentially with time,which is more obvious when the percentage of inorganic suspended matter accounting for total suspended matter is higher.When the suspended matter concentration is low,no clear relationship is found between settling velocity and suspended matter concentration.But settling velocity obviously rise with the increase of suspended matter concentration while the latter is high.