Abstract: For improving the quality of spun yarn, the break draft ratios of SKF drafting system have to be changed when two pressure bars are fitted additively. When the break draft ratio is too low, the twisted roving cannot be sufficiently draft in the break drafting zone, resulting in thick places in the spun yarn. When the break draft ratio is too great, a drafting wave in the drafting roving is caused, and the quality of spun yarn is influenced. The effect of the break draft ratios in SKF drafting system on CV value, thin places, thick places, neps, strength and elongation of spun yarn were analyzed. The results of our investigations reveal that when the break draft ratio is 1.35 with roller setting of 51 mm, the optimum spinning conditions are obtained for the roving of 0.545 g/m and 109 twist multipliers.