A study on the curves of the exchange ratio E(%)-pH on the liquid-solid interface of the systems Zn(II) with clay minerals (Kaolinite , illite and montmorillonite), Zn(II) with hydrous ferric oxides (amorphous ferric oxide, goethite and hematite). Zn(II) with hydrous manganese oxide (y-MnOOH, manganite and 5-MnO2) etc . in seawater resulted in the discovery of new plateau type exchange ratio ?%)-pH curves not yet reported in literature. The two factors that decide the growth , decline and the change of the “ plateau type ” curve are : (1) the inherent characteristics of systems , which can be explained by the exchange constants i(i=1 ,2 , 3 . etc .) of interfacial stepwise ion / coordination particle exchange between liquid and solid ; and (2)The theory of interfacial stepwise ion/coordination(the amount of solid exchange reagent)particle exchange in seawater was applied to explain the experimental results of the above study and a general formula was derived for the plateau type exchange ratio E(%)-pH c A study on the curves of the exchange ratio E (%) - pH on the liquid-solid interface of the systems Zn (II) with clay minerals (Kaolinite, illite and montmorillonite), Zn (II) with hydrous ferric oxides oxide, goethite and hematite). Zn (II) with hydrous manganese oxide (y-MnOOH, manganite and 5-MnO2) etc. in seawater resulted in the discovery of new plateau type exchange ratio?%) - pH curves not yet reported in The two factors that decide the growth, decline and the change of the “plateau type” curve are: (1) the inherent characteristics of systems, which can be explained by the exchange constants i (i = 1, 2, 3. Etc.) Of interfacial stepwise ion / coordination particle exchange between liquid and solid; and (2) The theory of interfacial stepwise ion / coordination (the amount of solid exchange reagent) particle exchange in seawater was applied to explain the experimental results of the above study and a general formula was derived for the plateau type exch ange ratio E (%) - pH c