Abstract: The storage period for jet fuel stored in cavern tank is 15 years in accordance with concerned regulation. If the storage period is more than 15 years, the characteristics of jet fuel will be changed or not, and what kind of measures should be taken to elongate storage period. A successful case, or answer, is presented in the article. The main measures taken to elongate the storage period for jet fuel includes keeping dry (anti-moisture) and reduction of evaporation loss of fuel, which is introduced in detail in the article.