The research object of the study was Chinese naturally fermented sauerkraut.The contents and kinds of free amino acids in sauerkraut were determined by amino acid analyzer.The results showed that Chinese naturally fermented sauerkraut were rich in 17 kinds of free amino acids.The total content was 635mg/L.The free amino acid with highest content was Thr,followed by Alu,Ala,Ser,Val and Asp.Chinese sauerkraut contained 7 kinds of essential amino acids and their content were 41.37% of the total amount.The 17 kinds of flavour amino acids played an important role in formation of Chinese sauerkraut flavor.