The methods of ion exchange-elcctrodcposition, ion exchange-precipitation for source-making, and for determining 65Zn in marine environment have been studied in detail. The chemical and radiochemical yields are 90% for organism and sediment, and 85% for seawater. They have good repeatability with a precision of 3%. The decontamination factors for radioactive nuclides are larger than 103. The preconcentration of seawater and the electrode position for source-making are significantly improved and can be used on thin and even source-measucing, applicable to low background β counting. The methods of ion exchange-elcctrodcposition, ion exchange-precipitation for source-making, and for for 65Zn in marine environment have been studied in detail. The chemical and radiochemical results are 90% for organism and sediment, and 85% for seawater. The decontamination factors for radioactive nuclides are larger than 103. The preconcentration of seawater and the electrode position for source-making are significantly improved and can be used on thin and even source-measucing, applicable to low background β counting.