A pulsed arc welding method using carbon dioxide gas alone or a mixed gas made mainly of carbon dioxide gas as a shield gas, provides a pulse current of alternately repeating first and second pulses as a weld current. The first pulse and the second pulse have a pulse waveform of a different pulse peak current level and a different pulse width, respectively, and the following conditions are satisfied: peak current of the first pulse (Ip1)=300 to 700 A; peak period (Tp1)=0.3 to 5.0 ms; base current Ib1=30 to 200 A, base period (Tb1)=0.3 to 10 ms; peak current of the second pulse (Ip2)=200 to 600 A; peak period (Tp2)=1.0 to 15 ms; base current (Ib2)=30 to 200 A; and base period (Tb2)=3.0 to 20 ms.