A liquid light-sensitive resin composition comprising:(A) a modified polystyrene resin which has at least one styrene unit having at least one ethylenic unsaturated double bond and at least one carboxyl group;(B) a polymerizable compound having at least one ethylenic unsaturated double bond;(C) a compound having at least one epoxy group;(D) a photopolymerization initiator or a photopolymerization initiating system;(E) a thermohardening catalyst capable of inducing a thermal reaction of the at least one epoxy group; and(F) an organic solvent; is disclosed. This liquid light-sensitive resin composition can form a bubble-free light-sensitive resin layer of a uniform thickness on a printed circuit board; allows both of photohardening and thermohardening by heating the printed circuit board, on which the light-sensitive resin composition has been applied, prior to the exposure so as to lower the tackiness of the surface coated with the light-sensitive resin composition and adhering the film and a pattern mask followed by exposure; is highly sensitive; gives a film excellent in electrical properties, mechanical properties and chemical resistance after hardening; and can be developed with an alkaline aqueous solution.