Abstract: A diglycidyl ether of bisphenol-A type epoxy resin (DGEBA) was modified by using liquid carboxyl-terminated butadiene acrylonitrile rubber (CTBN) and polyimide (PI) as combining impact modifiers, methylhexahydrophthalic anhydride (MeHHPA) as a curing agent and 2,4,6-tris(dimethylaminomethyl)phenol as a curing accelerator. The effects of CTBN and PI on the mechanical properties, dynamic mechanical properties and morphology of DGEBA were investigated. The results indicated that the Izod impact strength, fracture strength and elongation at break of DGEBA were significantly increased, while the modulus decreased slightly. The modified DGEBA achieved optimum mechanical properties when 20~30 phr of CTBN and 1.5~2.0 phr of PI were incorporated. Moreover, the presence of PI in an appropriate amount could enhance the storage modulus and heat resistance of DGEBA. The scanning electron microscopic observation indicated that the toughening effect was attributed to the plastic deformation of fracture surface.