The determination of 210Po in phosphoric acid reagent by alpha-ray spectrometry using extraction chromatographic resin is presented. The decontamination factors of interference elements were measured. It was observed that HCl, HNO3, ascorbic acid, thioacetamide and Cu were free from 210Po but Pb contain small amounts of 210Po. 210Po in phosphoric acid samples was ranged from <8 to 2.4 Bq/l. The detection limit of 210Po in 50 ml of phosphoric acid is 8 mBq/l with a counting time of 1 day undercounting efficiency of 30%.