This study is regarding development of an index table for antomation of welding process in impeller fabrication. A PLC, which is widely used for automation in industry, was also adopted as a controller for the index table because of it effectiveness, easy maintenance and repair. The index table consists of centering jig, blade jig, workbench, driving system and a controller. A touch screen was also prepaired as a man-machine interface to provide convenience for workers. Water jacket was installed inside the workbench to reduce thermal stress come from the welding. Temperature of the water jacket was kept constant to cool an impeller main plate effectively. The index table developed in this study convinces that it reduces the total welding time by 50% compared with the conventional process without the table.