Objective To establish and validate the ELISA method for the determination of porcine trypsin residues in attenuated Japanese encephalitis vaccine (JEV).Methods Double-antibody sandwich ELISA was used to establish a method for the determination of porcine trypsin residues in JEV. The accuracy, repeatability, intermediate precision, durability, linearity, specificity, and detection and quantification limits of the method were verified.Results The recovery rates of test samples ranged from 92.23% to 118.16%. Coefficients of variation (CVs) of the same batch were 6.6%-12.1%. CVs of the same batch was 8.1%-11.5%, 6.7%-8.5%, and 8.4%-9.6%, respectively, for different test personnel, different test dates, and different batch kits. Within the temperature range of (37±1) ℃, the recovery rates of samples showed no statistically significant difference (F=0.43, P=0.662). Coefficients of determination were > 0.98 in the range of 3.12-200.00 ng/mL. The method showed no cross-reaction with the substrate. The limits of detection and quantitation were 1.25 ng/mL and 3.12 ng/mL, respectively.Conclusion The method has good accuracy, repeatability, intermediate precision, durability, linearity and specificity, thus is suitable for the determination of porcine trypsin residues in JEV.