A new solid-state fermentation (SSF) reactor was developed for the spore production of biocontrol agent Clonostachys rosea. The greatest spore production in the reactor, 3.36 x 10(10) spores g DM-1 occurred with mixings, which was about 10 times greater than that in traditional tray reactor. The reactor provides about two times sporulation surface area for spore formation. Moisture content of the medium was adjusted to meet the spore production by changing the surface porosity. Two mixings were carried out during cultivation to make the medium loose, which resulted in a mass of new sporulation surface. The fermentation period shortened from 14-15 to 10-11 days. It is suggested that the new reactor has great potential in the mass production of spores of C. rosea and other fungal biocontrol agents.