In this paper,conventional analyses on biomass decline,glucose consumption rate,pH value and the enzyme activities,such as protease,chitinase,catalase,superoxide dismutase and glutathione peroxidases,were investigated for understanding the physiological and biochemical characteristics during the submerged fermentation of mrfA deletion mutant of Monascus ruber M7.Compared with the original strain M7,the biomass declined more quickly.During the whole fermentation,glucose consumption rate and the activities of protease /chitinase were all higher than those of M7.Obviously,the highest activity of protease occurred on Day 6.At the same time,activities of catalase /superoxide dismutase /glutathione peroxidases of mrfA deletion mutant were also higher than those of M7.All these results showed that mrfA deletion mutant showed typical autolysis characteristics in the growth process,which might due to high protease activity.Superoxide dismutase was the main antioxidant enzyme to cope with reactive oxygen species(ROS) damage.This study laid a foundation for further understanding of the autolysis mechanism of Monascus spp.