In this work, an electronic nose was used to evaluate the different cultivars and mature stages of melons, so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal component analysis (PCA) and linear discriminant analysis ( LDA ) showed that immature melons could be well distinguished from mature melons using electronic nose. VVhen PCA method was used to analyze, electronic nose could completely classify and identify the maturity of melons. Meanwhile, the electronic nose could distinguish different varieties of melons with high discrimination value. The flavor of samples under cut or no cut conditions would slightly change, leading to the variation of discrimination value among different varieties. The samples with similar flavor under no cut condition could be analyzed through cutting mode. The research built a rapid and accurate method to judge the maturity of melons instead of man sense.