The application of chemiluminescence (CL) analysis for the evaluation of staling beer was studied. Commercial Japanese lager beer was stored at 30°C, 37°C, and 60°C and its CL generation was analyzed at 60°C. The CL production was accelerated to a greater degree and its intensity reached maximum level more rapidly with increase in incubation temperature and/or time. The sum of the CL intensity for the first 1 hr showed a good relationship with staling degree in mean flavor panel scores. Therefore, CL determination may be useful for evaluating oxidation deterioration of beer.