Abstract: An epoxy resin aqueous composition of the room-temperature hardening type having improved rust preventive, anti-corrosive and weatherproof properties, which comprises an aqueous dispersion containingA. an epoxy resin having at least two epoxy groups per molecule, andB. a condensation product prepared by condensingI. a polyamine mixture of 4-aminomethyl-octamethylene-diamine and a polyalkylenepolyamine represented by the general formula (III)h.sub.2 n -- r -- nh -- (rnh).sub.n -- H (III)wherein R is a straight-chain alkylene group having 2 to 4 carbon atoms and n is 0 or an integer of 1 to 6, withIi. a reaction product ofA. an .alpha.,.beta. -unsaturated carboxylic acid or an ester thereof represented by the following general formula (I) or (II)y -- ch = cx -- y (i)y -- c .tbd.