Abstract: In the present study, the volatile flavor compounds in instant roasted fishes with different processing technologies were determined using Gas Chromatography-Ion Mobility Spectrometry（GC-IMS）, and their differences were compared and analyzed. The results showed that there were 50 kinds of volatile compounds detected and identified in four groups of roasted fish samples mainly including alcohols, ketones, aldehydes, hydrocarbons and esters.The main volatiles of TK samples（carbon baked） were aldehydes and ketones, such as 3-methylbutyraldehyde,phenylacetaldehyde, butyraldehyde, 6-methyl-5-heptenedione, etc; the main volatiles of P₁ samples（frying 8 min,140 ℃） were similar with those of TK samples in addition to olefins, such as α-terpinene, ocitene, limonene, etc;the main volatiles of P₂ samples（ frying 6 min, 160 ℃） were dihydro-furanone, 2,3-butanedione, etc; and the main volatiles of P₃（ frying 4 min, 180 ℃） and P₂ were partially same, including M-2-heptanone, 1-octen-3-ol, furanone, and so on. Compared with TK samples, there were significant differences on volatile components in P₁, P₂, and P₃ groups, and the volatile compounds types of P₂ and P₃ were similar. Through PCA comparative analysis, the contribution rate was 90%, and the difference of sample characteristics was obvious. Using GC-IMS technology to analyze the volatile compounds of instant roasted fishes would exhibit a superior application value for the improvement of roasted fish technology and optimization of product flavors.