Abstract: Arctii Fructus is the ripe and dry seed of Asteraceae herb (Arctium lappa L.), which has pharmacological activities such as anti-inflammation, anti-virus and anti-diabetes. Plant lignans arctiin and arctigenin, which are the main components of the traditional Chinese herb Arctii Fructus, can be converted to many different kinds of metabolites including demethylated arctigenin, enterodiol and enterolactone, through demethylation and dehydroxylation by animal intestinal flora. Current studies have shown that the microbial transformation products of arctiin or arctigenin have stronger and wider biological activity than arctigenin. This paper reviews the main components, the pharmacokinetics and the microbial bioconversion of Arctii Fructus, so as to accelerate the research and development of microbial metabolites of the main components in Arctii Fructus.