Abstract: Objective In the paper,solid phase microextraction(SPME) and derivatization with pentafluorobenzylbromide for free iodide and thiocyan in urine was presanted.Methods The derivatives of free iodide and thiocyan were extracted for 25 min at the condition of 80℃ temperature by a polydimethylsiloxane fiber.1,3,5-tribromobenzene(IS) was used as an internal standard.GC/MS was used for analysis.The ions at m/z 181(both of the derivatives) and m/z 312(IS) in the selected ion monitoring chromatograms were selected for quantitation.Results The compounds were detectable at least 0.01μg/ml.Conclusion This method would be demonstrated to be simple and useful.