The control of silver thickness is regarded as one of the most important things in the staple yarn manufacturing process, because the regularity of silver has a crucial role I determining the physical properties of spun yarn as well as the yarn evenness. In this study, an effective method for using the autoleveller that is used widely in the textile industry was suggested to improve the yarn quality and productivity. For this purpose, the dynamic behavior of the silver due to the changes in delivery spee was experimentally modeled. On the basis of the model, the optimal controller parameters were obtained. Then the controller parameters were applied to a real drawing frame to verify the control efficiency. Results of this study are as follows: 1) A mathematical model describing the behaviors of slivers at various delivery speeds in drafting process was identified. 2) The integrating time of the PI controller should be lowered with increase in delivery speed. 3) By applying the optimal controller parameters to the actual system, the regularity of silver thickness was improved, but the effect of the autoleveller on the yarn regularity was reduced at higher delivery speeds.