Abstract: In this study, gas chromatography-ion mobility spectrometry (GC-IMS) was used to analyze the volatile components of passion fruit of different maturity, and a method was established to quickly distinguish the flavor differences of fruits of different maturity. A total of 33 kinds of volatile organic compounds were identified by GC-IMS, mainly including five categories of alcohols, esters, aldehydes, ketones and terpenes. There were significant differences in volatile organic compounds between ripe fruits (60 days after flowering) and less ripe fruits (50 days after flowering), and the contents of most volatile compounds in ripe fruits were higher. Including ethyl DL-2-hydroxy-4-methylvalerate, 2-pentanone, butyl acetate, 2-heptanone, α-pinene, (E, E)-2,4-heptadienal, benzaldehyde, limonene, β-ocimene, 2-butanone, methyl butyrate, ethyl butyrate and ethyl acetate, etc; while a few volatile substances were found in higher levels in less ripe fruits, including isoamyl acetate and isobutyl acetate, etc. GC-IMS can quickly detect and discriminate the flavor characteristics and differences of passion fruit at different maturity levels. The results of this study can provide scientific basis and reference for the harvesting and quality control of passion fruit.