Degradation products of nucleotide in sardine stored up to 15 days in stored in boxes without ice, vacuum package (VP) and modified atmosphere package (MAP) at 4oC were investigated using a rapid HPLC method. Nucleotide degradation was more rapid in sardine stored in air than those stored in MAP and VP. The lowest value from production of ATP derivatives were observed in sardine held in MAP, followed by VP. ATP content was not detected under the three conditions. AMP and ADP levels were less than 0.2 μmol/g on day 0 in all cases. The shelf-life of fish stored in MAP was 12 days according to sensory assessment, at which the content of IMP, Hx and Ino were approximately 0.2, 0.7 and 0.6 μmoles/g, respectively. Although IMP and Ino showed fluctuations under all of storage conditions, Hx content increased linearly with storage time. Thus, it might be used as a freshness indicator for sardine stored under MAP and VP. The maximum levels of Hx compound were 0.79 μmoles/g for MAP and 0.75 μmoles/g for VP at day 15, respectively.