Abstract: Archaea is one of the most popular research,it not only could survive under extreme environment,such as high temperature,high salinity,strong acid,strong base and anoxic environments,but also exist in various ecological environments.With the huge abundance and the variety of metabolic product,archaea is playing a highly important role in the biogeochemistry processes in the world the study of archaea is important to elucidate the basic laws of life and movement,revealing the interaction between biology and environment.In the article,Methanoarchaea in rumen was introduced,and its diversity also was discussed based on the analysis of 16S rDNA,which has been applied to anaylze more extreme environments of marine archaea.Nowadays,16S rDNA technology is being expanded in the rumen archaeal research,and 16S rDNA gene library of methanogenic archaea was established to study its diversity of rumen archaea.