Seasonal changes of flora, vegetation structure, and primary production for the vascular plants were investigated in the disturbed bank, Daedaejae, one of the reinforced bank of Upo wetland, in Changnyeong-gun, Gyeongsangnam-do, Korea from October 2005 to October 2006. The flora of the whole study area, the fabricated and the non-fabricated bank area were composed of 78, 72, 75 taxa, respectively. Among all of them, hydrophytes, hygrophytes, and mesophytes were 3, 33, and 42 taxa, respectively. The naturalized plants were 20 taxa, which was 25.6% of 78 taxa distributed in the study area. Dominant species of the fabricated and the non-fabricated bank area was Equisetum arvense and Trifolium repens, respectively. Importance values of the naturalized plants such as Erigeron annuus, Humulus japonicus, Astragalus sinicus and Ambrosia artemisiifolia var. elatior were relatively high in both area. The species diversity indices(H') were 1.010~1.450, and those were relatively high in October and low in March in both area. Those of the non-fabricated bank area was higher than the fabricated bank area during the whole study period. The similarity indices(CCS) between two kinds of banks were 0.359~0.456, and was lowest in March and highest in August, the culmination period of the vascular plants. Net primary production in the fabricated bank area was $417.1\;g/m^2$, and those of Phragmites communis, Oenothera odorata, Miscanthus sacchariflorus were 179.5, 84.0, and $66.1\;g/m^2$, respectively. Net primary production in the nonfabricated bank area was $392.7\;g/m^2$, and those of Erigeron canadensis, Miscanthus sacchariflorus, and Phragmites communis were 102.5, 87.4, and $81.6\;g/m^2$, respectively.