Abstract: Celestite sample was decomposed by mixed flux and strontium in the sample was converted into strontium carbonate. The fusion disc was leached using water and the solution was filtered for separating SO2-4. The precipitant was then dissolved with HCl. After adding polyethylene ethanol the sample solution was heated to boiling and then diluted to the volume. A portion of the solution was taken into a 0.4 mol/L HNO3 medium and lanthanum was added as releasing agent and Sr in the sample solution was determined by flameAAS. The method is suitable for the determination of Sr in celestite samples with SrO content ≤50%.