Abstract: Mixtures of glycerol,sorbitol,amino acid,peptide,peptone,protein,chelator,antiseptic and so on as stabilizers were designed and prepared by means of experimental and orthogonal method.The anti-triazophos polyclonal antibodies (PAbs) coated on 96 microplates were treated with these stabilizers individually (37℃,1 h),then stored at 37℃ for 7 days.The immunoreactivities of the PAbs were determined by direct competitive ELISAs.PAbs were found to be stabilized under 3 stabilizers.After the further investigation of comparing the immunoreactivity,the affinity and the detection limit of the PAbs which treated with the three stabilizers individually,an optimized stabilizer was then selected.That was stabilizer 1 (m/m;glycerol 2.5%,amino acid 1.5%,peptone 3.0%,chelator 0.1%,antiseptic agent 0.01%).When the incubation of coated PAbs were in the presence of the stabilizer 1 ,with storage at 4~6℃ for half a year or 37℃ for 14 days,the relative immunoreactivity was 97.8% and 94.2%,respectively.And the affinity (I50 68.43 and 54.38 ng/mL,respectively) and the detection limit (I10,3.72 and 3.22 ng/mL,respectively) remained almost the same as those of the PAbs which were just coated on the plate without storage(I50 60.73 ng/mL,I10 3.11 ng/mL).Freeze-thaw test also demonstrated that the optimized stabilizer 1 was fit for the PAbs when the freeze-thaw was not more than 8 times.It indicated that the optimized stabilizer could improve the coated PAbs stability evidently,and could be applied to the production of the triazophos ELISA kit.