VapormateTM, the new gas formation of ethyl formate(EF) with carbon dioxide, is an MB(methyl bromide) alternative fumigant for grains and perishable commodities especially to control quarantine pest. To gain systematic efficacies of VapormateTM, vaporized gases in Tedlar bag were collected from liquefied gases in cylinder. Vaporized gases were used for collecting efficacy data to Tetranychus urticae, two-spotted spider mite, for 6hr at 26± 1℃. When applied 25, 51, 77 and 102 ml/L of vaporized gas for 6hr, mortality of T. urticae female adult were 83.3, 97.8, 100, and 100%, respectively, at 24hr after fumigation. Also, at 77 and 102 ml/L of vaporized gas for 4hr treatment at 26± 1℃, the mortality of T. urticae female was 96.7 and 97.8%, respectively. This preliminary result may help to understand further scaled-up VapormateTM fumigation applied with different type of commodities.