Objective: To develop and evaluate a beads-based light-initiated chemiluminescent assay (LICA) for quantitation of cow milk component (Bos d 5) specific IgG 4 antibody in human serum. Methods: The sIgG 4 -LICA was performed by incubated serum samples with biotinylated allergens, emission beads coated with mouse anti-human IgG 4 antibody and streptavidin-coated sensitizer beads. The reaction conditions of sIgG 4 -LICA were optimized and the analytical performance was evaluated. Results: The precision of intra-assay, within-day and inter-assay (coefficient of variation) were 1.78% to 3.13%, 6.65% to 8.41% and 7.94% to 12.30%, respectively. The functional sensitivity of this assay was 4.71 ng/mL. For the linear range, the sIgG 4 -LICA had a good linear relationship within the range between 28.13 and 1 800 ng/mL, and the linear regression equation was Y=0.98X-1.31(r 2 =0.997). Maximum dilution limit was 1∶64. The disturbing rates measured by adding hemoglobin, triacylglycerol, total bilirubin, acid resistance and biotin to human sera with different concentrations of Bos d 5 sIgG 4 were from -6.38% to 8.60%. Conclusions The sIgG 4 -LICA introduced in this study was demonstrated to have effective performance for quantitation of allergen-specific IgG 4 and can meet the need of clinical requirement.