Abstract: The method of tobacco rod weight control was promoted by altering the distribution pattern of the tobacco layer sucked on the suction band to achieve higher control precision. Based on the fact that the tobacco layer is increasingly dense in vertical direction from top to bottom, and an asymmetrical control method was developed by setting different conversion coefficients according to the weight deviation of tobacco rod and equalizing the weight variations of tobacco rods through adjusting the height of the pressing wheel (or ecreteur disc) when the positive and negative weight deviations approach the same absolute value. Further, an asymmetrical segmental control method is developed by specifying a deviation threshold value and setting segmental conversion coefficients for larger deviation and smaller deviation to improve control precision. The developed asymmetrical segmental control method was tested with cigarettes of two specifications made by China Tobacco Zhejiang Industrial Corporation Limited. The results showed that: 1) The differences between the proportions of heavier cigarette and lighter cigarette decreased by 4.31 and 3.31 percentage points respectively. 2) The long-term standard deviations of cigarette weight of the two specifications decreased by 16.5% and 9.9%, and the standard deviation of pressure drop decreased by 4.0% and 3.9%, respectively. This technology provides support for improving the physical quality of cigarettes.