An epoxy resin composition comprising 100 parts by weight of an epoxy resin and 30 to 120 parts by weight of polyalkylphenol having a number of constitutional units of formula (I) in its molecule as a curing agent wherein a represents an integer of 1 to 4. It is excellent in thermal resistance, toughness, flexibility, cracking resistance, mold release and hydrophobicity. <CHEM>
