An ion chromatography system for the determination of Indol-3-acetic was described. Ion chro-matograph was carried out by suppressed conductivity detection (DX-100T). The eluent contained 3mmol/l Na2CO3 and 3mmol/l NaOH. The detection limit was 0. 73μg/ml(S/N = 3). The relative standard deviation was 1. 88% for retention time, 4. 44% for height and 0. 51 % for area, respectively. The correlation coefficient of the calibration curve was 0. 9997 for area and 0. 9901 for height. The linear range was 1-1000μg/m...