Abstract: The variation of puff number and tar, nicotine, and CO deliveries of cigarette smoke with puffing interval was tested. The puffing interval was 30, 40, 50, 60, 70, 80, 90, and 100 seconds respectively. Two brands of cigarette were determined. The results showed that 1)the puff numbers and tar, nicotine, and CO deliveries of cigarette smoke were increased with the decrease of puffing interval, and 2)the tar, nicotine, and CO deliveries per puff cigarette smoke were almost constant with the change of puffing interval. It was concluded that puffing interval could directly influence the puff number and tar, nicotine, and CO deliveries of cigarette, but its effects on the tar, nicotine, and CO deliveries per puff cigarette smoke were negligible.