Abstract: In order to investigate the effect of multi-stage water extraction on organic acids extracting from raw material of paper-making process reconstituted tobacco,the contents of major volatile,semi-volatile,and nonvolatile organic acids in tobacco and residues from each stage were determined by gas chromatography-mass spectrometry(GC/MS).The results showed that:1) The contents of volatile,semi-volatile,and nonvolatile organic acids in tobacco and residues were significantly different.Generally,with the increase of number of extraction stage,the total amounts of volatile and non-volatile organic acids in residues decreased,while the total amount of semi-volatile organic acids increased.The major organic acids in tobacco and residues were oxalic acid,malic acid and citric acid,and their total amount decreased with the increase of number of extraction stage.2) The contents of semi-volatile organic acids and oxalic acid in residues were higher than those in tobacco.Multi-stage water extraction is effective for the extraction of most organic acids in tobacco,but it is not effective for extracting semi-volatile organic acids and oxalic acid from tobacco.