Today, composite materials have extensive use in aerospace automotive and defense industries compared to metals, because of their high strength to weight ratio and good corrosive resistance. Machining of these materials regard to their composite structure is complicated. Achieve optimal machining conditions, depending on the needs, according to the type of fiber and resin used in composites, need proper analysis and careful investigation. In this study, composite pipes made of glass-epoxy to a thickness of 5 millimeters, which are often used in the body of Aerospace structures, produced by hand lay-up and their surface roughness after turning process is measured. In order to obtain the minimum roughness in the turning process, tool type in two modes, and cutting speed, feed rate, and depth of cut are studied at three different levels. So Taguchi experimental design method and experimental test samples on roughness the results analysis and performed by minitab software. Finally, concluded that the minimum value of the surface roughness is obtained by tools with chip-breaking levels, cutting speed 100 m/min, feed rate 0.05 mm/rev, and the depth of cut 1.5 mm.