The objective of this study was to investigate changes in drying yield, pH, water activity, microbial growth, and storage stability of bottom rounds of Hanwoo beef under four different dry-aging treatments (T1–T4) as temperature (2~4℃), relative humidity (65~86%) and dry-aging period (20~90 d). The drying yield decreased by 83.13–97.05% as the drying period increased. Among the four treatments, there were no significant differences in drying yield after 60 d of dry-aging. The total plate aerobic counts (TPC) increased by 1.07–4.39 log colony-forming units (CFU)/g as the dry-aging period increased. Of the four treatments, T4 at 40, 60, and 90 d had significantly higher TPCs than those observed for the other treatments on the same days (p<0.05). As the period of dry-aging increased, pH values increased by 5.35– 5.88 for knuckle and 5.34–5.62 for sirloin muscle, and water activity values decreased. For knuckle and sirloin muscle, the water activity values at 40 d and 60 d of T1 and T4 were significantly higher than those of the other treatments on the same days (p<0.05). The thiobarbituric reactive substances and volatile basic nitrogen values of the aged products increased as the dry-aging period increased. The results of this study showed that dry-aging conditions such as those in the T2 or T3 treatments (with a gradual increase in temperature and humidity) for less than 60 d would be best for yield, reduction of microbial growth and storage stability by dry the muscle surface quickly at the beginning period. Further research should include meat quality and economic analysis for these conditions that examines the benefits of these dry-aged products for the end processor.