In the method desoribed,tho tungshsn in thiooyanate-hydrochlorio acid medium is first reduced.to pentavalent state by metallic lead or silver powder determined volumetrioally by titration with a standard ferrio solution.Since the tungsten thiooyanate oomplez is suffioiently stable in air,thismethod apears to give a good result and oan be applied to the analysis of tungsten ores.