A method for the evaluation of the uncertainty of amantadine in egg by ultra-performance liquid chromatography-stable isotope dilution mass spectrometry was established. Based on SN/T 4253—2015, the mathematical models of uncertainty was established and the sources of uncertainty were analyzed and evaluated, while the components of uncertainty were composed. The results showed that the expanded uncertainty was 4.9 μg/kg （k=2, 99% confidence interval） when the content of amantadine was 25.2 μg/kg, mainly caused by standard solution preparation and curve fitting.