A class-specific molecularly imprinted polymer（MIP） with strong selectivity and adsorbability for triazines and their metabolites was synthesized by bulk polymerization using atrazine as template molecule,methacrylate acid（MAA） as functional monomer,and trimethylolpropane trimethacrylate（TRIM） as cross-linker. And a rapid method was developed for the determination of 8 triazines and their metabolites in maize,wheat and cotton samples by molecularly imprinted solid phase extraction and high performance liquid chromatography tandem mass spectrometry（MISPE/HPLC-MS/MS）.The proportion of atrazine and methacrylate acid was screened and optimized by ultraviolet spectrometry.The morphology of polymer was observed with scanning electron microscope and transmission electron microscope.The recognition performance of structure analogues on the molecularly imprinted polymer was studied by HPLC-MS/MS.The result indicated that the synthesized molecularly imprinted polymer had a strong affinity and specificity for atrazine and its structure analogues,and the molecularly imprinted solid phase extraction cartridge had a good selectivity and purifying ability.The mean recoveries of these compounds in maize,wheat and cotton were in the range of 61.1%-107.6%,with relative standard deviations（RSD） below 11%.The limits of detection（S/N=3） were in the range of 0.4- 8.1 μg/kg. The MISPE-HPLC-MS/MS method could be applied in the routine surveillance of actual samples.