Epoxy resins have been used successfully as adhesives for many years. Despite many advantages of epoxy resins like high strength, chemical and heat resistance, in many applications they lack flexibility. During service under dynamic stress and variable environment this may lead to cracking and even failure of the adhesive joint. To improve epoxy resin adhesive performance they can be modified with other polymers. In this work modified silyl-terminated polyether polymer (MS Polymer) was used as elastic matrix material in various mixing ratio with epoxy resin. In the MS Polymer/epoxy blend A component consists from MS Polymer, amine catalyst, aminosilane and additional fillers. B component is based on bisphenol A diglycidyl ether (DGEBPA) epoxy resin with tin catalyst, water and fillers. When epoxy resin is mixed together with MS Polymer at the right ratio they form heterogenic matrix/domain structure which consists of the epoxy domains functioning as hard segments in elastic MS Polymer matrix [1]. When A and B components are mixed together, curing happens by epoxy reacting with amine catalyst, at the same time MS Polymer reacting with water. Aminosilane links MS Polymer with epoxy. Tensile stress-strain characteristics according to DIN 53504 were determined by using Zwick/Roell Z010 universal testing machine. Fracture surfaces of brittle-broken test specimens were observed by using Mira/LMU field emission scanning electron microscope (TESCAN a.s.).