In this research, Taguchi technique was applied to find out the optimum tool wear in CNC milling operation of magnesium silicide alloys with aluminum. A L9 orthogonal array, S/N ratios and ANOVA techniques are used to analyze the performance characteristics of spindle speed; feed rate and depth of cut as machining parameters with tool wear as responded variable. The result of the analysis reveals that the chosen machining parameters are affecting the tool wears drastically, while machining magnesium silicide alloys with aluminum and also point out the spindle speed is the most influencing parameter of compare to feed rate and depth of cut. At last, the results are confirmed by validation experiments.