The paper describes new procedures of extraction spectrophotometric determination of phosphates, based on the extraction of the ion associates of complex anions of 12-molybdatophosphoric acid, its “molybdenum blue,” and anion of 11-molybdatovanadatophosphoric acid with a cation of cationogenic tenside. The methods were applied to the determination of phosphorus in the samples of soil, plants, and water from lysimetric studies.