Abstract：Deep geological disposal of radioactive waste is considered worldwide as the most safe and feasible method to protect human being and the environment for tens of thousands years. A number of disposal concepts have been developed in many countries on the basis of a multi-barrier system, which comprises the natural geological barriers and the engineered barriers. In order to prove the disposal concepts，a great number of full-scale experiments have been performed at underground research laboratories constructed in different geological formations(rock salt，crystalline，argillaceous and tuff rocks). Besides of the development of adequate techniques for construction，disposal operation and backfilling/sealing of repositories，very comprehensive knowledge about geological，hydrogeological，geochemical and geomechanical properties of the host rocks at potential repository sites as well as deep understanding of coupled thermo-hydro- mechanical-chemical(THMC) processes occurring in the multi-barrier have been achieved. Typical disposal concepts and the associated in-situ experiments are represented.
