The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS( liquid chromatography tandem mass spectrometry). A total of 282 metabolites were stably detected in the two groups using OPLS-DA( orthogonal partial least squares discriminant analysis) method; 148 of which were down-regulated while 134 were up-regulated. After analyzed with MZ-mine software,10 major metabolites(4 down,6 up) were identified through searching public database. Aromatic compounds,3-p-coumaroyll,5-quinolactone,aromatic free amino acids,styraxin and methanofuran,were up-regulated; grease metabolites,methyl 15-hydroperoxy-9Z,12 Z,16E-octadecatrienoate,9,12,13-Tri-HOME( 10),3-oxo-dodecanoic acid,and 13( S)-Hp OTr E acid ester,were down-regulated; piperanine( alkaloids) was down-regulated while Methyl 7-epi-12-hydroxyjasmonate glucoside( indicant) was up-regulated. In a word,aromatic compounds and liquid metabolites may play vital roles in drought-resistant regulation of tall fescue. The total metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS (liquid chromatography tandem mass spectrometry). A total of 282 metabolites were stably detected in the two groups using OPLS-DA (orthogonal partial least squares discriminant analysis ); 148 of which were down-regulated while 134 were up-regulated. After analysis with MZ-mine software, 10 major metabolites (4 down, 6 up) were identified through searching public database. Aromatic compounds, 3-p-coumaroyll , 5-quinolactone, aromatic free amino acids, styraxin and methanofuran, were up-regulated; grease metabolites, methyl 15- hydroperoxy- 9Z, 12Z, 16E- octadecatrienoate, 9,12,13-Tri-HOME -oxo-dodecanoic acid, and 13 (S) -Hp ​​OTr E acid ester, were down-regulated; piperanine (alkaloids) was down- regulated while Methyl 7-epi- 12-hydroxyjasmonate glucoside (indicant) was up- a word, aromatic compounds and liquid metabolites may play vital roles in drought-resistant regulation of tal l fescue.