To industrialize meju, four kinds of meju (Korean-style soybean koji) were made with humidity-controlled fermentation for 12 days at $28^{circ}C$ after they were inoculated with selected strains such as Aspergillus otyzae (AO meju), Aspergillus sojae (AS meju), combined Aspergillus sojae and Bacillus subtilis (ASBS meju), and combined Aspergillus oryzae and Bacillus subtilis (AOBS meju) as starter microorganisms. The changes in the quality characteristics in the four kinds of meju were investigated during fermentation. Their enzyme activities were compared with those of the traditional meju that is made in Sunchang Folk Village according to the traditional method. In the meju that were inoculated with selective strains, the aerobic bacteria counts and mold counts exceeded 8 log cfu/g and 6 log cfu/g respectively, which were the highest fermentation values after 2 days. The aerobic bacteria counts were maintained from 2-day to the 12-day fermentation. The mold counts tended to decreased gradually after the 2-day fermentation. The amino-type nitrogen contents reached 430.5-577.5 mg%, which were the highest values after 2-day fermentation. The neutral protease activities of these mejus had the highest levels in the following order: traditional meju, $1,258.0{pm}38.8$; AS meju, $1,238.3{pm}38.6$; AO meju. $1,204.1{pm}24.1$; ASBS meju, $1,040.6{pm}10.6$; and AOBS meju, $1,033.5{pm}11.2$ unit/g. The acidic protease activities of these meju had the highest levels in the following order: AO meju, $1,030.1{pm}19.1$, traditional meju, $1,007.7{pm}30.5$; AS meju, $990.9{pm}25.0$; AOBS meju, $910.9{pm}15.3$; and ASBS meju, $888.2{pm}15.7$ unit/g.