Welded reinforcement mesh is proposed to cope with hard work of bar arrangement and shortage of labour workers when reinforcement concrete caissons for breakwater or revetment are fabricated. Strength of reinforcement is, in general, decreased when it is welded. Therefore usage of welded reinforcement is limited in construction work. Various problems as to strength properties are scrutinized through fundamental material tests for welded reinforcement and loading tests of concrete beams with welded reinforcement mesh. By welding, bending capacity of reinforcement and fatigue strength are decreased for certain. However reinforcement mesh can be applied for casisons for port facilities on condition that it is applied for small repeated stress level and no bending work.