This paper reports on a study of the influence of welding variables on the weld shape of Al-7020 in pulse-GMA welding. Five variables, i.e., wire feed rate, peak pulse current, welding speed, welding voltage, and pulse frequency were investigated for their effects on the weld shape.From the results of the 2n-l fractional factorial design, quantitative effects of each variable and the interaction of two variables were obtained, and consequently wire feed rate, welding voltage, and welding speed were determined as the main welding variables. Supplementary experiment was performed for investigating the detailed relationship between the main variables and the weld shape. In this experiment, the penetration of the weldment increased when the wire feed rate was raised, and the bead width increased when the welding voltage was raised or the welding speed was reduced.