Single-spot laser and twin-spot laser welding, with or without wire feeding, of aluminum alloy were carried out. The weld shaping, the thresholds of gap width and spot separation, and the states of porosity in weld with various laser welding procedures were compared, and the influences of twin-spot laser on welding of aluminum alloy were analyzed. It showed that in contrast to single-spot laser welding of aluminum alloy, twin-spot laser welding can improve the weld surface quality, increase the weld width and the thresholds of gap width and spot separation, decrease obviously the large porosities in number, but do not the small porosities. Feeding wire in process of single-spot laser welding of aluminum alloy can improve the weld surface quality, increase the thresholds of gap width and spot separation, but increase large porosities in number. Twin spot laser welding with wire feeding can decrease the large porosities in number.