Abstract: The present invention is directed to a weld line profile control method in weaving welding. According to this method, a welding current and/or a welding voltage in a position close to a weaving endpoint is evaluated as a reference value. A welding current and/or a welding voltage in the vicinity of an n-th (n.gtoreq.2) weaving endpoint are actually measured respectively, and thereafter an (n+1)-th weaving endpoint position is evaluated on the basis of difference between the actually measured value and the reference value. Further, welding from the n-th weaving endpoint to an (n+1)-th weaving endpoint is executed on the basis of the positional data. As the result, neither too much nor too little weaving welding can be performed.