Light and temperature variations are important during the vegetative stage of the Chinese red radish. We found that peroxidase (POD) and catalase activities and the content of pelargonidin were decreased by treatments of short of light perioid and low temperatures, while the content of hydrogen peroxide was increased. The POD isoenzymes of the radish organs were detected diversely depending on the developmental stages by polyacrylamide gel electrophoresis analysis; semi-quantitative RT-PCR revealed that expression was significantly induced during the flourishing anthesis stage in the bud. These results suggest that POD expression is both time-dependent and tissue-specific and that light and temperature conditions can influence the growth and antioxidant activity of the radish.