Spectrophotometric determination of rhenium according to thiourea method has been applied to rheniumtungsten alloy.A sample of the alloy was fused with a mixture of sodium carbonate and potassium nitrate, and it was dissolved in water and then diluted. An aliquot of the solution containing 0.12.0 mg of rhenium is taken in a volumetric flask and it is diluted to 100 ml, after 0.2 g of urea, 10 ml of 50% citric acid solution, 25 ml of concentrated hydrochloric acid, 12 ml of 5% thiourea solution and 6 ml of 1 M stannous chloride in 4 M hydrochloric acid solution beeing added, more than 50 minutes later, the absorbance is measured at 380 mμ. The method can be applicable to the rapid determination of rhenium in rhenium-tungsten alloy without separating any rhenium from a large quantity of tungsten.