Methylotrophy is a kind of widespread microbe which can use carbon compound as their only carbon and energy sources. It has been reported that methylotrophy can directly use one carbon compound to transform into their own metabolic one carbon unit, then these one metabolic one carbon units can be used as energy and carbon skeleton by organisms, which is a main part in one carbon metabolism. Because this is a novel metabolic system, it can be used in the study of biological metabolism and evolution. Based on the previous study about Methylobacterium sp. MB200 in our lab, here we summarized the research improvements about methylotrophy from their taxonomy, metabolism, genomics and applications.