Abstract:The gemma and gametophyte of Marchantia #olymorpha were propagated in vitro. Dedifferentiation and redifferentiation as well as the media used and cultural conditions reguired were described. Since the differentiation of bryophytes was very difficult, it was necessary to culture the tissue through initiation of partial dedifferentiation on MS agar medium supplemented with 1 mg/1 2,4-D and 3% sucrose, and then subsequently the tissue was transplanted onto 1/2 Knop agar medium with addition of 4–8 mg/1 2,4-D, 0.25–0.5 mg/1 BA and Fe salt of MS medium. The formed calli were visual but still contained rhizoid, in this stage. The small calli finally were subcultured in white agar medium supplemented with mixture of pyruvic acid, citric acid and fumaric acid (5 mmol/1); 1 mg/1 2,4-D and 4% glucose. They could be differentiated thoroughly into normal tissue. The time of the total process for differentiation requied as long as 10 months. The redifferentiation and regeneration of thalli were far easier than those of higher plants even if they were transplanted onto MS phytohormone-free medium.