In the present study, a low average power pulsed Nd:YAG laser is used for bead-on-plate welding of low carbon steel plate. The effect of laser process parameters on the weld quality and weld bead profile, welding penetration (P), welding surface width (W) and welding pool area (A), is studied. Focal point position, welding speed, pulse duration, and energy are selected as the process variables. The formation of a keyhole and weld bead profile is found to be highly dependent on laser pulse parameters. Results show that the maximum penetration accurse when the focal point is above the surface, in pulse duration of 6 ms, welding speed of 2 mm/s and pulse energy of 16.67 J.