The partitioning of the trivalent lanthanides (Lns(Ⅲ)) and actinides (Ans(Ⅲ)) is a key step of high level liquid waste processing in nuclear industry. Due to the very similar physical chemical properties between Lns(Ⅲ) and Ans(Ⅲ), their partitioning is so difficult as to be considered as one of the most challenging issues which has not been satisfactorily solved yet. For the partitioning of Lns(Ⅲ) and Ans(Ⅲ), there are two ways to be chosen in technology. One is to develop the lipophilic extractants with high selectivity for Ans(Ⅲ), and the other is to exploit the hydrophilic ligands with good coordination properties for Ans(Ⅲ). In recent years, the considerable progresses are made on both ways. In regard of the research and development for the latter, it is found that some water-soluble ligands such as complexones, water-soluble amides and pyridine derivatives exhibit good selectivity for Ans(Ⅲ) in aqueous solution. For the past few years, these water-soluble ligands as stripping or masking agents have been used for the separation of Ans(Ⅲ) from Lns(Ⅲ). In the present paper, the progress on the water-soluble ligands for the separation of Ans and the partitioning of Lns(Ⅲ) from Ans(Ⅲ) are reviewed from the following aspects: the influences on the extraction of Lns(Ⅲ) and Ans(Ⅲ); the composition and structures of complexes; as well as the thermodynamic properties for coordination reaction. In addition, some advices are also given for further exploration.

Contents
1 Introduction
2 Water-soluble ligands
2.1 Water-soluble amides
2.2 Complexones
2.3 Water-soluble pyridine derivatives
3 Conclusion and outlook