The objetive of the present study was to identify soybean (Glycine max L. Merrill) cultivars according to the electrophoretic profile of the isozymes a and b esterase (Est-EC 3.1.1.1), extracted of seedling embryonic axis of 34 cultivars after three days germination in the dark, at 25°C. Results showed that the isozyme zymograms of a and b esterase had a similar polimorfism degree for the studied cultivars. By the isozyme zymograms it was possible to separate the cultivars in five groups. As shown, it is clear that isozymes electrophoresis can be helpful in the caracterization of cultivars by grouping them according to a specific isozymatic profile.