Abstract: The peroxidase isozyme of 30 varieties of sugarcane during different growth period was analysed by using of vertical plate polyacrylamide gelelectrophoresis. The comparison of the isozymatic spectra of the same variety in different districts and in different leaf positions was also made. The results showed that there were significant differences among the enzymatic spectra of the different varieties, while there were no differences in the enzymatic spectra of the same variety in different districts, in different growth periods, in different plants and in different leaf positions. Thus, it indicated that the isozyme used as a variety label possess polymorphism and stability. The monoenzyme can be used precisely and conveniently for identifying the variety of sugarcane.