Monacolin K (MK) was produced on soybean using Monascus ruber GM011 by a two-stage-fermentation process. The optimal temperature was identified as $28^{circ}C$. Higher yield was obtained by multiple-level-temperature cultivation than by single-level-temperature cultivation. The highest yield of total MK, 4.810 mg/g dry soybean product, was attained after 30 days of solid-state fermentation. No citrinin could be detected in the fermented soybean.