an arc blowing control method and apparatus for use in a pulse arc welding system for preventing the extinction of the welding arc in the presence of current fluctuations or the like , thus preventing splattering of molten welding material and resulting in a smooth and continuous welding bead . a detection circuit is provided for electrically detecting the occurrence of a so - called stepped leader phenomenon during pulse arc welding and for generating a stepped leader signal accordingly . a switching unit is operated in response to the stepped leader signal for switching from a normal arc signal output to an arc blowing blocking signal output for a predetermined time . an arc blowing blocking circuit operates in response to the arc blowing blocking signal for effecting arc blowing suppression operations .