A novel method for the simultaneous quantification of seven metabolites of polycyclic aromatic hydrocarbon in human urine was developed using online solid phase extraction-HPLC with double ternary liquid chromatography system combined with fluorescence detector. The target compounds were online concentrated on the Turboflow Cyclone solid phase extraction column at first, then transferred by the six-way valve to the Hypersil Green PAH column for separation with acetonitrile and water as mobile phase at a flow rate of 1. 0 mL/min and at 35 ℃. A single sample analysis cycle took only 20 min. Under the optimized chromatographic conditions, the method showed good linear relationship ( r≥0. 999 ) in the range of 5-2000 ng/L or 50-20000 ng/L. The LODs were 0. 5-15 ng/L, and the recoveries were 80. 7%-110. 7%. The proposed method was successfully applied in the detection of metabolites of polycyclic aromatic hydrocarbons in urine from several smokers and non-smokers. The concentrations of 2-hydroxynaphthalene, 1-hydroxynaphthalene, 2-hydroxyfluorene, 2-hydroxyphenanthrene, 4-hydroxyphenanthrene and 6-hydroxychrysene in the smokers urine were much higher than that in non-smokers.