Abstract: As a facultative anaerobe,Lactococcus lactis has a double metabolic life,it could grow via a traditional fermentation metabolism under anaerobic conditions,its respiration could be activated when provided with heme and aerobic environment. Here,the genetics requirements,the dramatic physiology changes,the actual and potential application of respiration metabolism in L. lactis were discussed. In L. lactis,bacterial biomass,long- term survival,and resistance to oxygen and acid were impacts positively and significantly by respiration,which had great potential. With further research of aerobic respiration metabolism in L. lactis,new perspectives on understanding L.lactis lifestyle and exploiting its full potential can be opened.