Abstract: The fresh-keeping effect of Ctenopharyngodon idellus fillets with different treatments of young apple polyphenol ( YAP) extracts under the cold storage ( 0⁴℃) was studied in this paper.An electronic nose technology for evaluating the freshness of C.idellus was established through principal component analysis ( PCA) coupled with sensory evaluation and total volatile basic nitrogen ( TVB-N) as well as total bacterial counts. The results showed that the analysis of electronic nose were consistent with TVB-N and total bacterial count determination of C.idellus fillets and the most optimized concentration was 1g /L YAP.YAP had great development prospect as a kind of safe and edible nutrition preservative.It was suggested that electronic nose had good potential to detect freshness of C. idellus rapidly and non-destructively.