To improve the shelf-life of mushrooms, Lentinula edodes GNA01 mushrooms were treated with gel packs containing slow-released chlorine dioxide (ClO2) gas at 5~10 ppm for 5 days at 20℃ and the weight loss rate as well as the changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and ClO2 gas treated samples were decreased slightly, and there were no differences during the storage period. However, the weight of the control changed faster than those of the ClO2 gas treated samples during storage period. The pH in the control and in the ClO2 gas treated samples were decreased during storage period, but the samples treated with 5 and 7 ppm ClO2 gas were the least changed. On the other hand, the samples treated with 10 ppm ClO2 gas showed no difference from the other treatments during 4 days, but the pH was lower than that of the control on the fifth day. The lightness of inside and outside in mushroom were decreased whereas redness and yellowness were increased during storage period. However, color changes in the ClO2 gas treated samples were lower than those of the control. Especially, the samples treated with 5 and 7 ppm ClO2 gas were the least changed. The texture of the mushroom were decreased consistently during storage period. The texture of the control changed faster than those of the ClO2 gas treatments during 5 days. Especially, the samples treated 5 ppm ClO2 gas were the least changed.