A photosensitive resin composition in form of an aqueous emulsion comprising: a water-based, water-processable non-saponified and non-hydrolyzed vinyl acetate polymer to which at least one group selected from the group consisting of a styrylpyridinium group and a styrylquinolinium group has been added, the polymer being obtained by adding from 0.01 to 5 mole % of the at least one group selected from the group consisting of the styrylpyridinium group and the styrylquinolinium group to a vinyl acetate polymer having a polymerization degree in a range from 100 to 5000 and a saponification degree of zero, the styrylpyridinium group and the styrylquinolinium group being one or more of respective formulae in the following formulae and: wherein A represents: or wherein, R 1 is a hydrogen atom or an alkyl or aralkyl group which optionally contains a hydroxyl group, a carbamoyl group, and ether bond or an unsaturated bond; R 2 is a hydrogen atom or a lower alkyl group; and X - is a halide ion, a phosphate ion, a p-toluene-sulfonate ion, a methyl sulfate ion, an ethyl sulfate ion or mixture of two or more of said ions; wherein A is: or wherein, R 1 is a hydrogen atom or an alkyl or aralkyl group which optionally contains a hydroxyl group, a carbamoyl group, and ether bond, or an unsaturated bond; R 2 is a hydrogen atom or a lower alkyl group; and X - is a halide ion, a phosphate ion, a p-toluene-sulfonate ion, a methyl sulfate ion, an ethyl sulfate ion or mixture of two or more of said ions. a water-based, water-processable non-saponified and non-hydrolyzed vinyl acetate polymer to which at least one group selected from the group consisting of a styrylpyridinium group and a styrylquinolinium group has been added, the polymer being obtained by adding from 0.01 to 5 mole % of the at least one group selected from the group consisting of the styrylpyridinium group and the styrylquinolinium group to a vinyl acetate polymer having a polymerization degree in a range from 100 to 5000 and a saponification degree of zero, the styrylpyridinium group and the styrylquinolinium group being one or more of respective formulae in the following formulae and: wherein A represents: or wherein, R 1 is a hydrogen atom or an alkyl or aralkyl group which optionally contains a hydroxyl group, a carbamoyl group, and ether bond or an unsaturated bond; R 2 is a hydrogen atom or a lower alkyl group; and X - is a halide ion, a phosphate ion, a p-toluene-sulfonate ion, a methyl sulfate ion, an ethyl sulfate ion or mixture of two or more of said ions; wherein A is: or wherein, R 1 is a hydrogen atom or an alkyl or aralkyl group which optionally contains a hydroxyl group, a carbamoyl group, and ether bond, or an unsaturated bond; R 2 is a hydrogen atom or a lower alkyl group; and X - is a halide ion, a phosphate ion, a p-toluene-sulfonate ion, a methyl sulfate ion, an ethyl sulfate ion or mixture of two or more of said ions. wherein A represents: or wherein, R 1 is a hydrogen atom or an alkyl or aralkyl group which optionally contains a hydroxyl group, a carbamoyl group, and ether bond or an unsaturated bond; R 2 is a hydrogen atom or a lower alkyl group; and X - is a halide ion, a phosphate ion, a p-toluene-sulfonate ion, a methyl sulfate ion, an ethyl sulfate ion or mixture of two or more of said ions; wherein A is: or wherein, R 1 is a hydrogen atom or an alkyl or aralkyl group which optionally contains a hydroxyl group, a carbamoyl group, and ether bond, or an unsaturated bond; R 2 is a hydrogen atom or a lower alkyl group; and X - is a halide ion, a phosphate ion, a p-toluene-sulfonate ion, a methyl sulfate ion, an ethyl sulfate ion or mixture of two or more of said ions.