In this study, Mg2Si reinforced Mg alloy material was produced by adding 10 % Al12Si alloy ingot to Mg matrix by conventional casting method and then the melt was poured into a metal mould in cylindrical form. Machining tests were carried out on these cast alloys through single point turning method. Optimum machining conditions was aimed to be determined by investigating the effects of cutting parameters on surface roughness. For this purpose, the machining tests were performed without coolant on a CNC turning centre at four different cutting speeds (250, 350, 450 and 550 m/min), two different feed rates (0.1 and 0.2 mm/rev) and two different tool tip radii (0.4 mm ve 0.8 mm). The experimental design was conducted according to Taguchi's L8 orthogonal array. Machining experiments were carried out on CNC lathe under dry cutting conditions. ANOVA was used to determine the effect of cutting parameters on the surface roughness. According to the obtained analysis results, it was seen that the most influential parameters on surface roughness was feed rate by 57.6 %.