Abstract: Rotating arc GMAW welding method was used to weld low carbon steel. The effect of welding parameters including rotating frequency and welding speed were studied. The results show that welding spatter increases as the growth of the rotational frequency and the weld appearance is poor. When the rotating frequency is more than 70 r/min, the spatter significantly increased, welding process is unstable and the weld has a bad formation. The welding speed has no effect on spatter. The weld reinforcement increases at first, then stay a certain value as the rotating frequency increass, but decreases when welding speed increases. Rotating frequency and welding speed have little effect on weld width. Sectional area of the weld decreases with the increase in welding speed and rotation frequency has no contribution. Weld scales pattern spacing is inversely proportional to the rotating frequency, and proportional to the welding speed.