To develop epoxy based electrical insulation for HTS power cable and other device applications, the suitability of two cryogenic rated commercial epoxies, (MASTERBOND EP29-LPSP and EP37-3FLFAO) were evaluated. Characterization of their electrical breakdown characteristics, mechanical strength, and the interfacial shear strength of the interface with HTS tapes were conducted at room temperature and 77 K. The epoxy materials are ductile at cryogenic temperatures to support their use as electrical insulation of HTS power devices.