The size,composition,vertical distribution and species diversity of seed bank as well as its relationship with aboveground vegetation were studied in three dominant plant communities(Miscanthus sacchariflorus,Carex sp.,and Phalaris arundinacea) distributing with different water levels in Lake Dongting.The density of seed bank was highest in M.sacchariflorus(44656 seeds/m2),followed by P.arundinacea(31725 seeds/m2) and lowest in Carex sp.(15146 seeds/m2).Seeds in the seed bank distributed mainly within 0～5cm soil layer and decreased rapidly along with the soil depth.The seed banks of the three communities were composed of 53 species belonging to 18 families,39 genera.Among them,20 species were perennial while 33 were annual or biannual.The proportions of perennial species were 29.9%,35.2% and 38.0% in the soil seed bank of M.sacchariflorus,C.sp.and P.arundinacea communities,respectively.The diversity indexes of seed bank and aboveground vegetation were 0.76 and 0.53 in M.sacchariflorus,0.70 and 0.17 in C.sp.,0.72 and 0.45 in P.arundinacea,respectively.The similarity indexes between seed bank and aboveground vegetation were 0.28 in C.sp.,0.40 in M.sacchariflorus and 0.52 in P.arundinacea,respectively.The diversity index of seed bank was higher than that of aboveground vegetation and the similarity was relatively low.Therefore,perennial aboveground vegetation has limited contribution to the soil seed bank in large Yangtze-connected lake wetlands,where seeds might be mainly imported into seed bank through other pathways,such as water flow.