Abstract: Molecularly imprinted polymer(MIP) microspheres were prepared by heat-initiated-precipitation polymerization using Parathion, methacrylic acid(MAA), ethylene glycol dimethacrylate(EGDMA), azobisisobutyronitrle(AIBN) and acetonitrile as the template, functional monomer, cross-linker, initiator, and solvent respectively. The polymer particles were fixed on the electrode surface of the quartz crystal microbalance(QCM), then the response and the influence factor of the QCM such as the quantity of MIP fixed on the electrode and pH were evaluated. This QCM we use to detect Parathion in vegetables. The result showed that the MIP-coated QCM can effectively detect Parathion on removal of vegetables pigment is recsary in the pretreatment, and the detecting time is short. The QCM can be used to detect Parathion in vegetables.