Fusarium mycotoxin deoxynivalenol (DON) contents and its critical quality parameters were analyzed using two-rowed, six-rowed, and hulless barleys. DON content in the two-rowed Korean barleys was lower than that in the six-rowed barleys. The average DON contents of six-rowed, two-rowed, and hulless barleys were 1.35 ppm, 0.36 ppm, and 0.49 ppm, respectively. The DON content was reduced by 6.2% by sieving, by 6.0% by washing with water and by 18.1-69.8% by treatment with aqueous chemical solutions. Of the reagents investigated, aqueous sodium bicarbonate gave the greatest reduction in the barley DON level. The DON content was reduced to 62.5% of initial level after 3 days of steeping and to 23.1% after 3 days of germination. DON was not detected after steeping barley for 24 hr in 0.1M $Na_2CO_3$ solution with 0.1 % activated carbon.