Abstract: Safety evaluation of geological disposal of high level radioactive waste will takes into account the evolution of future biosphere at long time scales. The method of establishing the reference biosphere in the BIOMASS project is highlighted. The reference biosphere can be used to evaluate the specific site of high level radioactive waste. It is recommended to carry out the establishment of reference biosphere of Beishan high level radioactive waste repository as soon as possible.

Key words: High level waste, Geological disposal, Reference biosphere, BIOMASS project