A strong fibrin-specific fibrinolytic enzyme was produced from Bacillus subtilis KH-4 isolated from Deonjang, a Korean fermented soybean paste similar to Japanese miso. The addition of glucose as a carbon source resulted in the highest levels of caseinolytic and fibrinolytic activities. Likewise, the addition of yeast extract as the nitrogen source resulted in the highest caseinolytic and fibrinolytic activities (3473.2 unit and 47.4 munit, respectively), It was observed that out of all metal ion sources only calcium (chloride) enhanced caseinolytic and fibrinolytic activities, with increases of 4949.3 unit and 58.2 unit/mg, respectively. The optimal temperature for the production of the enzyme was found to be 4$0^{circ}C$ in the optimal medium (glucose 20 g, yeast extract 5 g, CaCl$_2$l g, and NaCl 2 g). The maximum fibrinolytic activity was observed at the late stationary phase. B. subtilis KH-4 produced a fibrinolytic enzyme at 4$0^{circ}C$, after 30 h growth, which increased up to 54 h and then remained constant. These results suggest that Deonjang has potential as a source of physiologically active anti-thromotic enzymes.