As the most famous perennial leguminous forage in the world,Medicago sativa L.ranks the first in both yield and nutritional value,and can be used for many years once planted in field production.However,root rot has become a very important reason for yield decrease and plant decline of alfalfa due to long service life.According to the research progress at home and abroad,the main pathogen distribution,harms and control methods of root rot in M.sativa at home and abroad were systematically expounded,in order to provide a theoretical basis for further research of the disease.