Abstract: Based on the sensors array made up of  four metal oxide semiconductor sensors which are cross sensitive to alcohol gas and organic, the realtime data acquisition was established in this paper, and the method of the steady and dynamic characteristic value extraction was proposed. Combined with principal component analysis（PCA）, three kinds of liquor were conducted classification experiments by the electronic nose system. The results show that the recognition rate of electronic nose system is up to 90.0% under the steady characteristic and 86.6% under the dynamic characteristic for the different brands of liquor.