The samples were decomposed with HNO3+HCl, and Fe3+-citric acid mix solution was added to eliminate interferences. The elimination and mechanism of tellurium interference with selenium determination by HG-AFS were studied, and the residuary influence of NO-3 and NO-2 was investigated. The interference of ferric trichloride, hydrochloric acid, citric acid and PBH concentration with the fluorescence intensity of selenium was observed by the orthogonal test design combined with the mono-factor test. The detection limit was 0.15 μg·L-1. The relative standard deviation of a solution containing 27.01 μg·L-1 selenium in sample was in the range of 3.1%~4.2% (n=11), and the recoveries of selenium were 96.1%～102.3%. The results obtained were satisfied, and the method was successfully applied to the determination of selenium in high purity tellurium samples.