Abstract: objective In order to find one of the best methods to make the extraction of alternaria alternate, in this study, we made different methods to compare the influence on the extraction allergen. Methods Alternaria alternate was gotten from the air and identified by Chinese Academy of Sciences, cultured under 26℃ for four weeks. Protein extracted by different methods and its concentration was determined using the Bradford assay， its bioactivity was tested by RAST inhibition, and residual proteins were analyzed by SDS-PAGE. Result The extraction methods, ranging from grinder（a）, grinder plus ultrasonic(b), ground with liquid nitrogen(c) and liquid nitrogen plus ultrasonic(d). The concentration of protein extractions were as follows （g/ml）: a was 0.44±0.04；b was 0.75±0.03；c was 0.72±0.03 and d was 1.29 ±0.05. From SDS-PAGE, we could find that we got the most component in the extraction by liquid nitrogen plus ultrasonic. From RAST, 50% inhibition as follows(μg/ml): a was 8.5, b was 9.4, c was 7.0,d was 3.7. Conclusion: Ground with liquid nitrogen plus disintegration by ultrasonic was the most effective method.