Diabetes mellitus is a degenerative disease characterized by an increase in blood sugar (hyperglycemia). α-glucosidase enzyme will increase the absorption of polysaccharide, dextrin, and disaccharide in the intestine, so that α-glucosidase enzyme inhibitors are needed to prevent glucose uptake in plasma. One of the plants that can be used as antidiabetic with mechanism of the α-glucosidase enzyme inhibitor group is eceng gondok herb (Eichhornia crassipes (Mart.) Solms). This study used ethanol extract of eceng gondok with variation of ethyl acetate fraction and ethanol fraction then analyzed the fraction using GC-MS (Gas Cromatography-Mass Spectroscophy) to see the compound of each fraction. This research also aims to know the interaction between ethyl acetate fraction and ethanol fraction of ethanol extract of eceng gondok herb with α-glucosidase enzyme. The ethyl acetate fraction obtained contained are 2-pyridinepropanoic acid, .alpha.-methyl-.beta.-oxo-, ethyl ester; 1-propanol-1-di; carbamic acid, methyl ester; acetic acid, aminooxo-, hydrazide; (2R) - [2-2H2] glycine methyl ester hydrochloride. While the ethanol fraction obtained contained are semicarbazide hydrochloride; carbonic dihydrazide; hydroxy-acetaldehyde; 1-propanol-1-di; acetic acid, hydroxyl. The compound further analyzed by docking with the α-glucosidase enzyme. Results of docking with α-glucosidase enzyme is 2-pyridinepropanoic acid, .alpha.-methyl-.beta.-oxo-, ethyl ester of the ethyl acetate fraction having the highest ΔGbinding is -4.14 Kcal/mol. While semicarbazide hydrochloride from the ethanol fraction has the highest ΔGbinding of -3.17 Kcal/mol.