Abstract:The structure of suspended particles and the sedimentary flux and sinking velocity in sea cucumber, Apostichopus japonicus Selenka ponds were studied. The results showed as follows: (1) The concentration of total suspended particular matter (TS) varied from 46.0 to 132.0 mg/L with an average of (73.1±20.5) mg/L; The concentration of inorganic particular matter (IS) varied from 28.5 to 76.5 mg/L with an average of (50.6±12.6) mg/L was 69.13% in TS; The dry weight of plankton (PZ) varied from 0.064 to 2.814 mg/L with an average of (0.675±0.706) mg/L was 0.92% in TS. Of which, the dry weight of phytoplankton (DWP) ranged from 0.062 to 2.582 mg/L with an average of (0.541±0622) mg/L was 0.74% in TS, and the dry weight of zooplankton (DWZ) ranged from 0.002 to 1.160 mg/L with an average of (0.135±0.200) mg/L was 0.18% in TS. Particular debris and bacteria ranged from 4.18 to 83.86 mg/L with an average of (21.91±19.59) mg/L accounted for 29.95% of TS. (2) The sedimentary flux of total suspended particular matter was (19.44 ±16.34) g•m-2•d-1 which varied from 6.33 to 91.98 g•m-2•d-1; Sinking velocity was (0.30±030) m•d-1 which ranged from 0.08 to 1.63 m•d-1. The sedimentary flux of nascent suspended particulate matter in the Apostichopus japonicus Selenka ponds was (5.09±7.30) g•m-2•d-1，which ranged from 0.14 to 31.27 g•m-2•d-1. Both the sedimentary flux of total and nascent suspended particulate matter in the bottom of ponds were higher than those in surface water.