Electron beam (EB) curing of polymer matrix composites offers many particular advantages compared to conventional thermal curing．There has been a considerable development about the EB curing advanced composites for the use of aerospace and other industries in recent years．Most variety of epoxy resin has been confirmed to possess radiation reactivity and have already become chief resin matrix used in EB curable composites．The dynamic mechanical analyses on EB-cured epoxy resin were made in the paper．Epoxy resins with varied chemical structure

molecular weight and distribution index were used in the EB radiation experiment．The variation regularities of gel fraction

damping factor and dynamic modulus for different samples were studied．The experimental results indicate that the radiation reactivity of epoxy resins is directly associated with their chemical structures．Phenolic aldehyde epoxy resin exhibits high radiation reactivity

glass transition temperature and high temperature modulus after curing. But the radiation reactivity of alicyclic epoxy resin is low．The curing level of epoxy resin descends slightly with increasing molecular weight under low radiation dosage

but the glass transition temperature is enhanced．The molecular weight has a little influence on the enhanced extent of curing level with increasing radiation dosage and the degree of homogeneity in cross-linked structure is improved for samples with high molecular weight．The glass transition temperature is under the influence of curing density at high reaction level．Similarly

the curing density is key factor to determine modulus of cured samples

but the molecular weight plays chief role in the samples with similar curing density．The reaction extent in sample with high polydispersity is higher under same radiation dosage

but the degree of homogeneity in cross-linked structure is lower than that of low polydispersity sample．