The objective of this study was to investigate the supplementation effect of selenium on beef color stability. A total of 15 Hanwoo steers were divided into 3 groups and 2 groups were administered with 0.9 ppm of one of two organic-selenium products, Organic-Se and Se-SMC (Se-spent mushroom compost) for 4 mon. The third group was the control group, which was not with fed selenium during the same period. The result of this study showed that there was no significant difference in meat color between the control and treatments when Hunter L * , a * , b * , chroma, hue and total color difference (∆E) were measured after 30 min of blooming. When the oxymyoglobin (OxyMb) contents were measured after beef samples were ground and stored for 48 h at 20 o C in an incubator, they were 26.04%, 28.52% and 33.78% for the control, Organic-Se and Se-SMC after 14 d of storage and 12.65, 18.98 and 18.72 after 21 d of storage at 4 o C, respectively (p<0.05). The control had a significantly higher metmyoglobin (MetMb) content than Organic-Se and Se-SMC (p<0.05). This result indicated that selenium supplementation was effective in preventing the oxidation of myoglobin(Mb) and production of MetMb and thus was able to maintain the purplish fresh red color of the meat.