Abstract: In the view of weld form,weld pore,joint mechanical properties,microstructur and joint anti-erode performance,etc,A-TIG(activating-tungsten inert-gas) welding for TA15 titanium alloy has been studied.The experimental results show that compared with conventional TIG(tungsten inert-gas) welding,A-TIG welding can increase weld bead penetration while decrease weld bead width,and can decrease the number of pore effectively,also can enhance joint tensile property and bend property.Heat-affected zone of A-TIG welding is narrower,and its microstructure is finer in comparison with TIG welding,while their microstructures of weld zone are almost same.The activating flux doesn't affect joint anti-erode performance.A-TIG welding is superior to conventional TIG welding for TA15 titanium alloy.