Abstract: In order to evaluate the freshness of grass carp ( Ctenopharyngodon idellus) stored at 0℃, changes in total viable counts, total volatile basic nitrogen ( TVB- N) , color difference value, pH value, ATP breakdown compounds and K value were investigated by periodically determination. The volatile odor that released in the process during the cold storage was determined and analyzed by electronic nose.It was showed that the TVB-N value, K value and total viable counts value of grass carp stored at 0 ℃ increased with the extension of storage time. pH decreased first and increased afterward. Chroma value fluctuated obviously. Electronic noses could distinguish grass carp under different time. The TVB- N value, total viable counts were significantly positivecorrelated with K value ( R2= 0.9136, R2= 0.9612) . The physical and chemical indicator could effectively characterize the freshness of the grass carp, and have good corresponding relationship.