The liverwort, Marchantia polymorpha L., is an emerging model plant. During the past several years, various molecular biological techniques for M. polymorpha have been developed. Recently, we reported an easy Agrobacterium-mediated genetic transformation method, for M. polymorpha, which is termed AgarTrap (Agar-utilized Transformation with Pouring Solutions). AgarTrap method could be carried out only by exchanging appropriate solutions in a single Petri dish within a week, and it could produce a sufficient number of independent transformants. Because AgarTrap is rapid and easy technology, this method will promote molecular biological study of M. polymorpha.