Abstract: Variation on the chemical compositionof root exudates from Tieguanyin tea plants that had grown for different numberof years under continuous cropping was determined to decipher the effectsinduced by the planting practice. Rhizosphere soil specimens from the fields,in which Tieguanyin tea bushes had been continuously cultivated for 0, 1, 10,and 20 years, were collected. After a methanol extraction on the soilspecimens, the chemical composition of the exudates was analyzed using agas chromatograph-mass spectrometer (GC-MS). Orthogonal partialleast squares discriminant analysis (OPLS-DA) and analysis of variance were performed on the data to identify keydifferential compounds among the samples. The results showed 52 substances that included13 organic acids, 11 carbohydrates, 16 alcohols, 4sterols, 2 phenolic acids, 1 diterpene, and 5 others. Indicated by the OPLS-DA, only minutedifferences were found between the 10-year and 20-year samples, but significantvariations between those and the 0-year and 1-year counterparts. Among the rootexudates, 18 displayed significant chemical differences by the number ofplanting years. The longer the continuous cropping, the higher relativecontents of 5 alcohols (i.e., 2-monopalmitoylglycerol,2-monostearoylglycerol, eicosanol, nonacosanol, and xylitol), 3 carbohydrates (i.e., galactinol, isomaltose, and maltose), 4-hydroxy-3-methoxybenzoicacid, DL-beta-hydroxybutyric acid, and heptadecanoic acid, but the lowercontents of 4 carbohydrates (i.e., fructose, galactose, glucose, and mannose),mannitol, pentadecanoic acid, and phosphoric acid in an exudate. Prolonged continuouscropping changed the composition as well as the content of root exudates ofTieguanyin plants. Further studies on the allelopathic autotoxicity of the keyroot exudate, 4-hydroxy-3-methoxybenzoic acid, and the chemotaxis of certainsugars on the rhizosphere microorganisms are in order.