Abstract: Manganese superoxide dismutase (Mn-SOD) is a metal enzyme widely existing in animals,plants and microorganisms,which can scavenge superoxide anions. As the first line of defense against superoxide anion,the expression and regulation of Mn-SOD in the mitochondria play an important role in balancing the homeostasis of redox. At present,many researchers have studied the preparation,extraction and functional application of Mn-SOD. This paper summarizes SOD's function,source,extraction and application,also expound Mn-SOD's production by genetically engineered bacteria and its application situation and development potential in medical and agriculture,so as to provide reference for the further development and utilization of Mn-SOD products.