PURPOSE: To obtain a low viscosity epoxy resin composition to be cured into a high strength complex by incorporating three kinds of specified resinous epoxy compounds and an aromatic amine curing agent.

CONSTITUTION: (A) About 47-56 wt.% of glycidyl ether of formula I ((a) is 0.5-3) as a reaction product of bisphenol A and epichlorohydrin and having about two epoxy groups per one mole, (B) (a) a glycidyl ether of bisphenol A different from A, (b) about 12-50 wt.% of the blend of a copolymer of ethylhexylacrylate and glycidylmethacryalate in a ratio of 50/50-95/50, (C) about 16-28 wt.% of neopentylglycol glycidylether of formula II, and (D) aromatic amine curing agents of formula III, formula IV, and formula V in enough amounts to generate a resin precursor having an amine/epoxy ratio of 1.11/1 are incorporated to obtain the objective epoxy resin blend suitable for resin transfer molding and wet filament winding.