The modified epoxy resin was synthetized from epoxy resin via opening all oxyran rings by dietanolamine and aminoamide of linseed oil fatty acids then mixed with fully blocked toluendiisocyanate by trimetylolpropan and 2-etylhexanol. The resin mixture was neutralized by lactic acid in water to form an emulsified system for the cathodic electrodeposited paint. The film forming conditions were studied and characteristics of film on carbon steel were investigated.