A study on the variation of the air temperature in the pine mushroom box containing dry ice for the preservation of the freshness of the pine mushroom, Tricholoma matsutake (Ito et Imai) Sing. produced in Korea was made in Seoul, Korea during the period of August 1 to 30, 1975. A safe shipment of 5 kg (net weight) of fresh mushrooms with freshness preserved for 24 hours in August required the placement of 4.5 kg of dry ice-a half in the upper portion and the other half in the middle portion-in an airtight container (mushroom box). The container used for the shipment test, made of 3mm-thick double-layer cardboard, was of the dimensions : $0.33{ imes}0.4{ imes}0.5=0.066(m^3)$. As the temperature fell, decreased amounts of dry ice were needed : 3 to 2 kg in September and 1.5 to 0.3 kg in October. With this preservation method, large quantities of fresh mushrooms were exported to Tokyo ana Osaka, Japan without damage in the process of transportation.