Synthesis and properties of epoxyfumarate and epoxymaleate resins obtained by the addition of acidic ester of maleic acid to the commercially available resin, Epidian 5, is presented. In acidic ester preparation, n-hexanol was used. The resins were synthesized in one- and two-step procedures. In the two-step procedure, acidic hexyl maleate was synthesized separately and then used for the addition reaction with epoxy resin. In the one-step synthesis, acidic ester was formed during the synthesis process. Properties of the obtained resins were compared.