Indole-3-acetic acid（IAA） imprinted polymer microparticles were synthesized using IAA as template,acrylamide（AA） as functional monomer and ethylene glycol dimethacrylate as crosslinker in acetonitrile porogen via precipitation polymerization.Effects of amounts of IAA and acetonitrile utilized in the polymerization reaction on the binding performances of IAA imprinted polymers were evaluated by high-performance liquid chromatography（HPLC）.The results showed that the IAA imprinted polymer P7 with the highest affinity（k=4.24） and imprinting factor（IF=14.1） for IAA was obtained when the molar ratio of IAA to AA 1∶1 was adopted with 2 mmol of IAA in 37.5 mL of acetonitrile porogen.Furthermore,P7 was chosen as the packing material to make the molecularly imprinted solid phase extraction（MISPE） column,and the MISPE method was developed for the purification of IAA .Under the optimized extraction conditions,the mungbean sprout samples spiked with IAA were extracted,and the recoveries of IAA ranged from 90.6%to 92.6%.The results demonstrated that the IAA-imprinted polymer particulates prepared using AA as the functional monomer by precipitation polymerization could be used as the adsorbent of solid phase extraction column for the selective separation and purification of IAA in real samples.A new route was proposed in this paper to synthesize an imprinted polymer with high affinity and high selectivity by means of increasing amount of template appropriately in the pre-polymerization mixture.