Abalone long-line culture is a commercially important mariculture method in China.With the development of scale,it is very important and necessary to understand its influence on the environment.In this paper the effects of abalone long-line culture on the water quality were studied,in order to provide basic information for the setup of sustainable mariculture mode.Dissolved nutrients were investigated in abalone long-line mariculture area of Sungo Bay in April,June,August,October and December of 2009.Water quality was assessed by organic pollution indices (A) and eutrophication assessment indices(E).Nutrient factors limiting the growth of phytoplankton were assessed by the method of theoretical half-saturation constant(K_s)and stoichiometric ratios.By comparison of nutrients in abalone,kelp and no mariculture areas and the historic data,the environmental influence of abalone longline mariculture was analyzed.Results showed that the concentration of dissolved inorganic nitrogen(DIN),PO3-4,and SiO2-3 were at the range of 2.73〖CD*2〗9.25 μmol/L,0.086〖CD*2〗0.42 μmol/L,0.91〖CD*2〗18.35 μmol/L,respectively.In April,June and December,A values were lower than 0,water conditions were in good level,in August and October,A values ranged between 0 and 1,water conditions were at preferable level.E values ranged in 0〖CD*2〗0.5,which showed that the nutrient concentration was in the poor nutrient condition.This result suggested that the influence of abalone longline culture on the water quality was limited.However,there were some extent variations between different areas in the nutrients concentration,nutrients structure and seasonal changing trend.P might be the key limitation in the monitoring area.From the historic changing trend,ammonium and DIN enrichment in abalone area in August should be paid more attention to.