Abstract: In order to investigate the influence of cut rag distribution in cigarette on the deliveries of ammonia and tar in mainstream cigarette smoke (MCS), cigarette samples with different filling density at two ends (Sample A, higher filling density at the lit end and lower at the filter end of cigarette; Sample B, consistent filling density; Sample C, higher density at the filter end and lower at the lit end) were made with the same materials. The deliveries of ammonia and tar in MCS were compared and the results were discussed on a puff-by-puff basis. The results showed that:1)Puff-by-puff smoke deliveries changed with the change of cut rag distribution, then affected the deliveries of ammonia and tar in MCS; 2) Comparing with the control, Sample B, the deliveries of ammonia and tar in MCS of Sample A and C reduced somewhat, and Sample C reduced more significantly.