Abstract: Industrial tannic acid is dissolved by hot water. The solution is refrigerated and settled. The settled solution is treated with ioncxchangc resin. By means of refrigeration-settle and ion exchange, tannic acid content is increased up to more than 92%, residual content of combustion is decreased less than 0.0031% sodium ion is 0.0083% and these are no fewifcrous and lead ion in the product. Tannic acid quality comes up to the technical index for reagent grade tannic acid.