Abstract: The optical and pneumatic filter rod circumference control systems were compared in terms of control accuracy, stability and resistance to disturbance, their working principles and control means were analyzed. The comparison was carried out separately on filter rod makers with optical and pneumatic control system to produce filter rods with tow both of the same specifications, and the produced filter rods were sampled and tested. The results showed that:the mean circumference of the samples produced by filter rod makers with optical control system was 24.1019 mm and that with pneumatic control system was 24.0962 mm, their standard deviations were of 0.0310 and 0.0504 mm, the short-term process capability indexes of 3.22 and 1.99, and the long-term capability indexes of 3.20 and 1.96, respectively. It indicated that optical circumference control system has the advantages over pneumatic control system in terms of control accuracy, response speed, stability, and resistance to disturbance.