CNC machine is widely used by manufacturing engineers and production personnel to quickly and effectively set up manufacturing processes for new products .This study discusses an investigation into the use of Taguchi Design methodology for Parametric Study of CNC milling operation for Surface Roughness, Material Removal Rate and Machining time as a response variable. The Taguchi design method is an efficient experimental method in which a response variable can be study, using fewer experimental runs. The control parameters for this operation included: Spindle speed, Feed rate & Depth of cut on EN 19 & EN24 alloy steel. A total of 16 (L16 Orthogonal array) experimental runs were conducted using an orthogonal array and the ideal combination of control factor levels was determined for the Surface Roughness, Material Removal Rate and Machining Time. The Taguchi method is to be employed by using MINITAB-16 software to identify the level of importance for the machining parameters.