Abstract: Based on the national standard analytical method for determination of molybdenum in uranium ores (GB/T 14353.9—1993) and using stannous chloride as reducing agent, potassium thiocyanate as a complexing agent and synthesized national grade I spectral silicate reference material as standard sample, the effects of different sample digestion methods and acid media on detection limit of molybdenum were studied. The determination parameters of molybdenum in uranium ores by thiocyanate spectrophotometry were further optimized. The detection limit of the method for Mo was as low as 10.0 μg/g with the advantages of high reliability and simple operation. The method has been applied to the determination of Mo in uranium ores and the results are in agreement with those by ICPAES.