This study was performed to observe the isoenzymes of soybean cultivars (Glycine max (L.) Merril) for esterase activity making use of amidogel. Seeds of twenty soybean cultivars were tested: IAS-1, IAS-2, IAS-4, IAS-5, BR-1, BR-2, BR-3, LC 72871, LC 728753, Hood, Bragg, Bossier, Hamptom, DavisBienville, Missões, Mineira, Sulina, Hardee and Viçoja. The tissues utilized in the analysis, were: hypocotyl and radicle of seedlings germinated at three days, with light and temperature of 25 ºC. The Scandalio`s method (1969) was used for the buffers and for substratum and colorific on the sterase revelation. The esterae activity revaled about six bands for all the cultivars. The anode showed one band faster and forteen slower. It was observed that there were variations in the cathode migration, also. Apparently, the cultivars that showed faster bands in the anode corresponded to those that presented slower ones in the cathode. It was possible the separation of the cultivars in two groups, the first one with six cultivars and the other one with fourteen.