Abstract: Bentonite pellet mixtures are considered as an alternative buffer/backfilling materials for high-level radioactive waste(HLW)repository. The packing and hydro-mechanical behaviour of bentonite pellet mixtures are of great significance for the safety evaluation of the HLW repository. In this paper, previous researches on the packing and hydro-mechanical behaviour of bentonite pellet mixtures are systematically reviewed and summarized. They include the packing dry density and homogeneity, water retention, structural change, hydraulic behaviour, swelling and compression behaviour as well as constitutive model. Meanwhile, several research subjects worthing further investigation are pointed out. Results in the literature indicate that the packing behaviour are highly dependent on the gradation. Upon wetting, the initial loose-structured pellet mixture can gradually transfer to cemented state and finally present a homogeneous appearance at saturation, accompanied with pellet breakage and movement, which can in turn affect the hydro-mechnical behaviour. Considering the complexity of the operation conditions in a HLW repository, further investigations on the emplacement technique and the hydro-mechanical behaviour under coupled thermo-hydro-chemo-mechanical conditions should be carried out.