Abstract: The effects of arc voltage,welding current and heat input on the weld appearance in submerged-arc welding(SAW) of A105 steel with small diameter welding wire were experimentally researched.Relationship between the arc voltage and the welding current was established,the optimum matching values between them were obtained,and the relationship of the heat input with the weld width was qualified to assure the optimal weld appearance through lots of experiments of bead-on-plate.This study not only offered some useful experiences for narrow gap SAW,but also established experimental foundation for the optimization of welding procedure of SAW with small diameter welding wire.