Abstract：The deep geological disposal scheme is widely accepted for high-level radioactive waste disposal in the world. The conceptual design of “multi-barrier system”，man-made and natural barriers，is adopted for disposal repository in the scheme. The natural barrier is a very important safe guarantee for repository operation in long term. The selection of reliable natural barrier depends mainly on the work related to geology，hydrogeology and geochemistry. Through the review of high-level radioactive waste disposal research in home and abroad，the key scientific issues related to geology，hydrogeology and geochemistry in the high-level radioactive waste disposal research are explained in detail；and the mainly content，method and means used in the investigation for disposal site are introduced. The hydrogeological，geochemical issues regarded in the world at present，such as hydrogeological and hydrogeochemical modelling，migration of radionuclide in the natural medium，the interaction among groundwater-waste-rock，the geochemical closeness of rock mass and so on，are also discussed.
