Four different methods including shaking, ultrasonic, boiling water and oven used to extract Fluorine (F-) in acid soils by water were compared in this experiment. And then the concentration of F- was determined by Ion Chromatogram (IC). The results showed that 20 min extracting time and 60℃ treating temperature were the optimal extraction conditions for the methods of shaking and ultrasonic when the ratio of water to soil was 5:1. No significant difference in the concentrations of F- was found between these two methods and their standard deviations were both lower than 0.3%. Furthermore, the concentration of F- extracted by ultrasonic was significantly higher than those extracted by boiling water or oven in their optimal conditions, respectively. Quality controls were carried out during the experiment and the values were within one standard deviation. Therefore, the methods of ultrasonic and shaking will be effective to extract F- in acid soils, especially for determination of batches of soils in laboratory.