To establish a method for determining benzo(α)pyrene in the air by high performance liquid chromatography after ultrosonic extraction,the specimens were extracted by ultrosonic wave with acetonitrile,the target compound was separated by HPLC with fluorescence detection. The column was Agilent Zorbax SB C18 column and the mobile phase was methanol-water in the ratio of 9∶1(V/V). The method has advantages of simplicity,celerity and less amount of organic solvents,and could be widely used for analyzing the ben...