Abstract: The distributions of longitudinal and transverse residual stress in of 3 mm-thick and 5 mm-thick marine 5 series aluminum alloy welded joints with and without reinforcement were measured by ultrasonic method，the joints were prepared by TIG welding with filler wire．Compared with 5 mm-thick plate，the results show that longitudinal residual stress in 3 mm-thick plate near weld zone was slightly lower because the large deformation can release part of the stress before removing the weld reinforcement．The longitudinal tensile stress is the highest near weld zone，and there is a compressive stress zone on both sides of the test plate．After removing the weld reinforcement，the double-peak feature of the longitudinal residual stress distribution with maximum stress near the weld zone．The removal of the weld reinforcement has few effects on the release of the longitudinal residual stress，but the transverse residual stress can be appropriately reduced．