A method for forming a wiring pattern by laser irradiation includes the steps of coating a light-sensitive material on a substrate to form a light-sensitive layer, irradiating a laser beam on the light-sensitive material of the substrate to form a pattern including an exposed region exposed to laser irradiation and an unexposed region unexposed to laser irradiation, and forming a metallic wiring pattern by immersing the substrate into a solution having a plurality of metallic nano-particles. The metallic nano-particles are easily bonded to the straighter molecular structure of the light-sensitive material in the exposed region for forming a conducting wiring pattern. The laser irradiation method has advantages such as high-power, high-density, high-directionality and monochromaticity, such that product quality can be effectively controlled. Moreover, the laser irradiated light-sensitive material can form a molecular structure that is easily bonded to the metallic particles. As a result, the chemical wastes are substantially reduced.