Abstract: This research work was devoted to the domestic made A186 carding machine,and a dynamic mathematic model was established for it using the data acquired on the spot with the least square method.A fuzzy controller was designed based on the relation between import and export of the linear density of the cotton sliver.The effect of the auto-level was evaluated with the performance index of the output cotton sliver.Simulation results show that the variance of linear density of the output cotton sliver is apparently smaller for an adjusted fuzzy controller than that for the PID controller.