Abstract: To investigate the effects of ultrafiltration membrane on components and sensory quality of tobacco extracts, membrane combinations of five levels(10 kDa, 2 kDa, 1 kDa, 700 Da and 300 Da)were designed to study the variations in the main chemical components and their contents in the retentate at each membrane level. The retentates were add into reconstituted tobacco for sensory evaluation, and the results showed that:1) From 2 kDa to 300 Da, the contents of reducing sugar and total alkaloids in the retentates of membranes of five levels increased gradually, the sum of reducing sugar in the retentate and filtrate of 300 Da membrane was more than 200% of the sum of reducing sugar in the retentates of the other membranes, and more than 70% of the total alkaloids in tobacco concentrated in these two parts. 2)The protein and polysaccharide enriched in the retentate of 10 kDa membrane, and the contents were 1.23% and 4.03% of the extract of original tobacco, respectively. 3)The characteristic components in tobacco had different enrichment characteristics on 700 and 300 Da membranes. The number of small molecular compounds in filtrate of 300 Da membrane was the largest. The total content of volatile components in filtrate of 300 Da membrane was the highest excluding nicotine, and the total amount reached 207.81 μg/g based on the extract of original tobacco. 4)The retentates of 10, 2 and 1 kDa membranes had more negative sensory effects in the reconstituted tobacco, while the retentates and filtrates of membranes below 700 Da promoted the sensory quality of reconstituted tobacco, and the top notes and body notes of the extract of original tobacco were prominent. The results of this study provide references for the development of tobacco flavors and quality reconstituted tobacco.