This paper deal with box column built-up by partial penetration welding at the corners. The objective is to propose the evaluation method of full plastic strength of beam-column joint panel of box column built-up by partial penetration welding which is considered about the influences of loading direction, aspect ratio, axial force and welding penetration depth of corner seams. Firstly, from loading test and finite element method analysis, we evaluate the structural performance of panel zone and the influences of above parameters on full plastic strength. From the results, we propose the evaluation method of full plastic strength.
