Abstract: The polymorphism of peroxidase isozymes of the common wild rice, particularly China and India common wild rice was studied by using isozyme electrophoresis methods. The results were:1) 24 bands of peroxidase were separated in the common wild rice. The frequence of differential hand is different from each other. The frequence of the 3rd, 5th, 6th, 9th, 10th, 11th, 19th, 20th, 21th and 22th bands is equal to 50 percent and more, among which the 3rd, 20th, 22th appear the most frequently. This suggests that the 10 bands can be treated as the basic zymogram, and the 3th, 20th, 22th may be the original bands of peroxidase in the common wild rice.2) The zymograms of peroxidase in China and India common wild rice differ, however are similar to in the basic zymogram and the original band.Therefor, although the comlnon wild rice shows higher polymorphism of peroxidase, its specific molecular characters are obvious. According to the study of peroxidase isozymes, the origin of cultivated rice and the evolution of the common wild rice are discussed. The significance of peroxidase isozymes in evolutionary studies is also discussed.