The present invention relates to one kind of weather resistant hot roller narrow steel strip for welded structure and its production process. The steel strip has the chemical composition comprising C 0.07-0.12 wt%, Si 0.25-0.50 wt%, Mn 0.30-0.50 wt%, P 0.07-0.15 wt%, S less than 0.035 wt%, Cu 0.25-0.40 wt%, Cr 0.30-1.2 wt%, Ni 0.10-0.50 wt%, and Fe and inevitable impurity for the rest. It is produced through smelting in a top blown converter, LF refining, continuously casting steel strip billet and hot rolling in a continuous rolling mill train. It has high purity, excellent corrosion resistance, excellent welding performance and homogeneous mechanical performance. It may be applied in making square welded tube or other accessories for container.