The thrombolytic enzyme, nattokinase, could be produced by the solid-phase culture of barley with Bacillus natto NB-1. Nattokinase production reached its maximum level after 1 day of fermentation at 37°C, and then gradually decreased. However, in the presence of a high concentration (1.0 M) of urea, the production level was increased and continued for a longer time. The final product had very strong nattokinase thrombolytic activity (>100, 000 IU/100 g dry weight), as well as amidolytic activity for Suc-Ala-Ala-Pro-Phe-pNA, H-D-Val-Leu-Lys-pNA, and Suc-Ala-Ala-Ala-pNA. Very high concentrations of vitamin K2 (menaquinone-7; about 9, 500 μg/100 g dry weight) and free amino acids, including Phe, Val, Tyr and Glu, were also confirmed.