Abstract: [Objective] To evaluate the uncertainty of the readout results of antibiotic content (chloramphenicol and fluoroquinolones) in raw milk using Colloidal Gold Immunochromatographic Assay. [Method] The "Yirui Chloramphenicol Single Test Rapid Detection Test Strip" ^[1] was used for chloramphenicol content measurement, and the "Yirui Fluoroquinolones Antibiotics Rapid Detection Test Strip in Milk" ^[2] was used for fluoroquinolones content measurement.By analyzing the sources of uncertainty, a mathematical model was constructed. Each part of the model was analyzed and evaluated, and the relative standard uncertainty was synthesized and further expanded to obtain the expanded uncertainty of antibiotic content (chloramphenicol and fluoroquinolones) in raw milk. [Result] At a confidence level of 95%, the readout results of antibiotic content in raw milk were: X（chloramphenicol） = 3.20±0.059 6, with k=2 and an expanded uncertainty U=0.059 6; X（fluoroquinolones） = 3.00±0.059 4, with k=2 and an expanded uncertainty U=0.059 4. [Conclusion] The uncertainty in the experimental process mainly originates from sample repeatability, sampling volume, test strip reader, and uncertainty introduced in result calculation. This method can provide a reference for uncertainty evaluation of antibiotic content in raw milk measured by immunoassay（colloidal gold immunochromatography）.

Key words: immunoassay, raw milk, colloidal gold immunochromatography, antibiotics, uncertainty