Abstract: This paper discusses the feasibility of manufacturing low toxicity and low hydrogen electrodes by means of test of perpendicular design, adopting a slag system of MgO-SiO₂-TiO₂-MgF₂.Emphasis is placed on the functions of different fluorides, rare earth melals and other chemical compounds in this slag system.Their influences upon the welding properties,the amount of fumes generated and particularly the soluble fluorides,are investigated.A new type of low toxicity and low hydrogen T507 grade electrode with good welding and mechanical properties has been developed.