Abstract: The elect ron beam ( EB) curing characterizations of bisphenol A epoxy resins and phenolic aldehyde epoxy resins with different diluent s were investigated. The effect s of the kind and content of diluent s on the gel massf raction , curing uniformity , cure dimension , glass t ransition temperature ( T_g ) and dynamic modulus for differentsamples were analyzed. It can be found that the use of diluent s in the epoxy resin systems will reduce the gel massf raction , T_g and storage modulus of EB cured epoxy resins , while it will improve the curing uniformity. The curedthickness of the epoxy resin with diluent is smaller than that of the resin without diluent , while the cure diameter ofepoxy resin with diluent is larger. With the increasing diluent content , the gel mass f raction decreases gradually , thecure thickness increases , and the cure diameter increases at first and then decreases.