This paper presents an experimental investigation of longitudinally welded aluminum I-section beams subjected to concentrated force. The specimens were fabricated using 6061-T6 heat-treated aluminum. The test program included 10 beam tests contained 2 test series according to different welding section, i.e. T-shape section and P-shape section. The test results were compared with the design strengths predicted by the European Code and the suggested formula in the paper for welded aluminum beams. The purpose of this paper is to present the tests results of two typically longitudinally welded I-section aluminum beams, and to validate the accuracy of the recommended design formula.