In this study, it is aimed to investigate experimentally the effect of cutting speed and cutting current parameters on width of heat affected area and surface quality of the cut surface in plasma arc cutting processes, which are widely used in industrial applications and to determine the most suitable parameters in terms of these outputs. For this purpose; the test specimens prepared from Hardox 500 material with a thickness of 20 mm were cut in CNC plasma arc cutting machine in combinations of two different cutting currents (130 and 260 amperes) and five different cutting speeds (725, 750,775, 800 and 850 mm / min). It has been found that the increase of cutting speed and cutting current increases the surface roughness. It has been observed that the increase of cutting current increase width of HAZ and HTZ, while increase of the cutting speed decreases the width of the heat affected zone (HAZ) and heat transfer zone (HTZ). It was determined that micro hardness values of HAZ decreased towards base metal, increase of cutting speed increased micro hardness values while increase of cutting current decreased micro hardness values. This situation; It was interpreted to fast cooling of HAZ.