In this study, we used an experimental design to investigate the influence of the total draft, break draft, distancebetween the aprons (Clips) and production roller pressure on yarn quality in order to obtain optimum draftingconditions for polyester and viscose (PES/CV) blend yarns in ring spinning frame. We used PES fibers (1.4 dtex ×38 mm long) and CV fibers (1.6 dtex × 38 mm long) to spin a 20 Tex blend yarn of PES (70%)/CV (30%) blend ratio.When the break draft, adjustment of distance between of aprons and roller pressure is not reasonable, controllingand leading of the fibers is not sufficient for proper orientation of the fibers in the yarn structure to produce a highquality yarn. Experimental results and statistical analysis show that the best yarn quality will be obtained underdrafting conditions total draft of 38, 1.2 break draft, 2.8 mm distance between of aprons and maximum pressure ofthe production top roller.