Abstract: In order to minimize the breakage of cut tobacco of low grades during the process of pneumatic feeding,the temperature and relative humidity setting in cut tobacco storing room was optimized,its effects on the long strands reduction before and after pneumatic feeding were analyzed,and the cut tobacco reduction and cigarette quality before and after optimization were compared,the results showed that:1) the optimal temperature and relative humidity were 28℃ and 71%,respectively;2) after optimization,the long strands reduction before and after pneumatic feeding for two cigarette makers reduced by 1.53% and 1.45%,respectively,and the moisture content variations of cut tobacco decreased by 0.2% and 0.11%,respectively;the average long strands reduction before and after rod forming section dropped by 0.675%;the average tobacco loss from cigarette end decreased by 0.4 mg/cig.,the average individual cigarette weight decreased by 0.01g,the average draw resistance dropped by 6 Pa,and the cigarettes' smoking quality became better.