Abstract: The effect of agglomerated flux's SiO₂ content on slag removal performance of submerged arc welding of stainless steel containing Ti and Nb was investigated. The results showed that with decreasing of the total amount of SiO₂ in agglomerated flux, the starch level of submerged arc welding with ER321 and ER347 also reduced; that as the total amount of SiO₂ was within the scope of 7.55%~8.15%, agglomerated flux matching ER321 and ER347 welding processes and contributing to deposited metal of good properties could be obtained.