This research determined the threshold value of 10 specified offensive odor substances based on the 3 point comparison sensory method. The panelist\'s thresholds were calculated by taking the arithmetic, geometric mean, and 50th percentile. Three methods of calculating the odor thresholds from the same data are compared. For 10 odor substances, the panelist\'s thresholds revealed a logarithmically normal distribution. The 50th percentile was the best method among the three methods of calculating the odor threshold from the 270 thresholds of 18 panels. As a result, the threshold values of individual odor substances, including i-valeric acid, n-valeric acid, n-butyric acid, and butyl acetate ranged between 0.0001~0.006 ppm, while the values of methyl ethyl ketone and toluene were relatively higher than that of other substances at 0.7107 ppm and 1.2139 ppm, respectively. The threshold values of the 10 specified odor substances were compared in Korea and overseas, which showed that the characteristics of sensory response varied by substance and nation. Keywords : Odor threshold value, Specified offensive odor substances, Air dilution sensory test, 50th percentile, Fatty acids