Abstract: In order to investigate a characterization method for fruit decay procedures, experiments of decay procedures on apple, pear, peach, plum, and grape decay procedure using electronic nose system were conducted. The decay degree feature was extracted by non-linear stochastic resonance technique. The feature gas amount during apple decay procedure kept going up，while the feature gas amount of pear, peach, plum, and grape reached their maximums, and then declined. The results showed that the electronic nose system characterized fruit decay procedure successfully, which provided a new way for fruit decay characterization.