Extracted solutions in four Alum processing Chinese herbal Medicines were obtained by ultrasonic and acid extraction method. Aluminum in the solutions was determined by Graphite furnace atomic absorption spectrometry at Hypo-sensitive wavelength. Extraction conditions were optimized. Methodological investigation on determination was also studied. The result was compared with wet digestion method，which shows that this is a quick and accurate method for determination of aluminum in some Alum processing Chinese herbal medicines.