In today’s manufacturing systems most of the time manufacturers, for retaining their position in the market competition, depends on manufacturing engineers and various production personnel in the industry. To get benefits of quick and effective setups while developments of a manufacturing processes for new products. For the manufacturing challenges, the Taguchi parameter optimization method is a powerful and efficient tool for quality and performance output. This thesis discusses on the parameter optimization of CNC lathe machining for surface roughness using the Taguchi method, where surface roughness generated during machining. In the parameter optimization, the parameters are cutting speed, feed, and depth of cut. After selecting parameters turning on CNC lathe is to be done and selected orthogonal array and parameters used for the optimum set of combined controlled parameters for surface roughness. Into this combination of parameters selected for minimum surface roughness value and for the optimum combination of parameters by Taguchi design. Taguchi orthogonal array L9 for three parameters cutting speed, feed rate, and depth of cut with its combination surface roughness measured, analyzed and recorded by signal to noise ratios.