A novel strong cation exchange monolithic column was prepared in a stainless steel column（4.6 mm in diameter） via the free radical polymerization of sodium methyl allyl sulfonate（SMAS） as monomer and ethylene glycol dimethacrylate（EDMA） as crosslinking agent.Scanning electron microscope image showed the resultant monolithic column matrix exhibited a continuous,porous and uniform structure.The on-line cleanup solid phase extraction was realized on the monolithic column and the determination of clenbuterol in pork was carried out by high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.The result indicated that clenbuterol in pork sample was effectively enriched and purified by the prepared monolithic column.The calibration curve was linear in the range of 0.05-10.0 μg/L for clenbuterol with a correlation coefficient of 0.998 8.The limit of detection（LOD） for clenbuterol in pork was 0.5 μg/kg,which agreed with the standards regulated by the National Standards of the People’s Republic of China.The average recoveries at three spiked levels of 0.5,1.0，5.0 μg/kg were 91%,94%and 96% with relative standard deviations（RSDs） of 4.9%,4.5% and 3.4%,respectively.With advantages of simplicity,reliable and sensitivity,the method was successfully applied in the determination of clenbuterol in pork samples.