PURPOSE: To method to prolong the period of fresh state of shellfishes, wherein the gathered shellfishes such as live short-necked clams are subjected to vacuum packaging, and presserved at low temperature.

CONSTITUTION: Shellfishes such as live gathered short-necked clams are soaked in seawater at about 13°C for about 8hr and sand is removed. Short-necked clams with broken shells are removed from the short-necked clams from which sand is removed, and they are purified by selecting the particle size, etc. They are washed with fresh water, and shellfishes such as the purified short-necked clams, etc. are divided into parts with a proper number, they are subjected to vacuum packaging with dehydrating them as much as possible, and preserved at low temperature at 2W10°C. By this method, the shellfishes can be preserved and controlled in fresh state immediately after gathering for more than one week even in summer, and economic efficiency can be commercially raised by efficient gathering and rational control.