Drying can endow aquatic products with unique flavor, whose formation is related to endogenous enzymes. In this study, the effects of different drying methods on enzyme activities and their metabolites inosinemonpho sphate (IMP) and free amino acid contents of Muraenesox cinereus fillets were investigated. Several enzymes playing the leading role in taste substances (such as AMP deaminase, acid phosphatase, cathepsin B and leucyl aminopeptidase) were selected. The drying methods included controlled freezing-point vacuum (CFVD), vacuum freeze drying (VFD) and hot air drying (HAD). Results showed that potential activities of the four enzymes mentioned above were decreased after drying. The highest retention of enzyme activities of fillets was observed in VFD, representing 92.99%, 85.58%, 65.53% and 54.26%, respectively, followed by CFVD. While HAD fillets had the lowest enzyme activities. The IMP and free amino acid contents in CFVD fillets were significantly higher than those in other treatments. IMP content increased from 174.37 mg / 100 g (dry basis) to 625.08 mg/100 g and free amino acid content increased by 33.07%. Therefore, four kinds of enzyme in CFVD fillets reach better retention in activities and the highest conversion rate.