Abstract: An analytical method for antimony in FCC catalyst by flame atomic absorption spectrometer has been established, which studies the influences of the counteracting time, counteracting temperature and acidity on the measuring result. The optimum conditions are also obtained. The recovery yield ranges from 95% to 99%, the relative standard deviation is below 2.5%, and the detection limits of Sb is 0.092 mg/L, accuracy and precision of this method are acceptable.