Alkyl resorcinol epoxy resins (diglycidyl oligomers) are produced mainly from concentrates of 5-alkyl resorcinols extracted from shale oil water-soluble phenols. Manufacture of epoxy resins is effected in two stages: synthesis of basic resins from alkyl resorcinols and additional treatment of ordinary resins for the purpose of making products with improved quality. Characteristic data for uncured resins are given for the products with epoxide equivalent mass from 120 to 2000 g/mole. These materials include modified alkyl resorcinol epoxy resins from commercial production, low-viscosity alkyl resorcinol epoxy resins with improved quality, high-purity crystalline diglycidyl ethers of alkyl resorcinols and solid thermoplastic alkyl resorcinol epoxy resins.