Abstract: Carnitine acetyltransferase plays an important role in β-oxidation of fatty acid.Candida tropicalis can assimilate n-alkane as a sole carbon source and produce dicarboxylic acids.Starting from a DCA producing strain, F10-1, CAT single and double-knockout strains, CZ-15 and CKC-11 were constructed.The results showed that CZ-15 had the same growth characteristics as F10-1, and due to inhibition of β-oxidation, CZ-15 increased DCA13 yield and molar conversion of alkane; however, CKC-11 could not grow on alkane, and the growth was suppressed.By the established metabolic flux model, the data were calculated and analyzed.Based on the results, more details of the metabolic pathway of glucose and fatty acid in Candida tropicalis were given.