The acid decomposition-extraction-spectrophotometric method of determining the rhenium concentration in molybdenum ores and flue dust was introduced. The conditions such as dissolution methods, extraction, absorption curve and determination were investigated systematically. The optimal condition of rhenium measurement was obtained based on a series of tests. The concentration of rhenium in different molybdenum ores and flue dust was determined by the proposed method; the relative standard deviation (RSD) of the method is below 3.5 %. Compared with ICP-AES standard addition method and alkaline fusion-extraction spectrophotometric method, the method gets satisfying results