The process of obtaining phosphorous fertilizer modified by magnesium and azote using the local natural raw – dolomite and industrial wastes of solutions of sulphate ammonium and phosphorous acid has been investigated. The decay of apatite by sulfuric acid in the presence of magnesium carbonate crude-dolomite has been studied. This method allows to substitute 50%  expensive deficit apatite by dolomite, to reduce consumption of sulfuric acid, enrich fertilizer with additional nutritious element-magnesium  and  azote, at the expense of increasing decay of crude in the camera product to exclude its stage of store growth, simplify the process, reduce contaminating environment by flour gases and superphosphate dust, considerably diminish length of technological cycle, improve economic and ecological  indices of phosphorous fertilizer production.