Abstract: The mechanical teasing and metering conveying in tobacco hopper in PASSIM cigarette maker has the shortcomings of higher tobacco breakage, larger standard deviation of cigarette weight and higher rate of loose end cigarettes. By comparing with its counterparts in GD121 and PROTOS cigarette makers, the system was improved as following:1)removing metering roller and picker roller in the initial metering unit, to which the higher tobacco breakage was attributed;2) composing a secondary metering assembly with a metering needle roller, a metering chute and a small needle roller;3)redesigning excess tobacco returning assembly to avoid repeated tobacco trimming;4)modifying the collector tube by adding an automatic cleaning function. After improvement, a comparative test was conducted, the results showed that the average tobacco breakage reduced from 17.52% to 15.31%, the standard deviation of cigarette weight and loose end cigarettes decreased obviously, and the running stability and performance were improved.