Abstract: In order to improve the smoking quality of paper-making process tobacco sheet, the extract of tobacco stem or tobacco fines was filtrated by M50(Ø50 nm) microfiltration membrane, GU ultrafiltration membrane 1(nominal retentive molecular weight 50000 Da) and GM ultrafiltration membrane 2(nominal retentive molecular weight 100000 Da). The filtrated liquid was added back into tobacco sheet, and its smoking quality was evaluated. The results showed that comparing with the extract without filtration:1) the total nitrogen in filtrated extracts of tobacco stem and tobacco fines declined by 62.5% and 67.8%, respectively, and all pectin substances were removed substantially; 2) the smoking quality of tobacco sheet to whom the filtrated liquid was added was improved to some extent, particularly those sheets to whom the extract filtered by M50 microfiltration membrane + GU ultrafiltration membrane 1 was added. It was practicable to improve the smoking quality of paper-making process tobacco sheet with the membrane filtration technology.