Abstract: Although a lot of research results on groundwater level against floating(GWLAF)have been achieved in China, there are many disagreements among them, which not only affect their practical applications to engineering, but also lead to the lack of systematicness and continuity in research itself. In order to solve this complicated and urgent problem, the basic concepts of the GWLAF, a methodology on two basic problems (pore water pressure and the highest forward groundwater level) and the technique systems of GWLAF are reviewed systematically and analyzed objectively, on the basis of hydrology, hydraulics, soil mechanics and other scientific theories and methods. In the aspect of the basic concepts of the GWLAF, according to the theory of occurrence of groundwater and seepage, they are classified into three types, i.e. a two dimensional concept, a quasi-three dimensional concept and a three dimensional concept, which are then formulated respectively, and analysis of the logical relationships between the three types of concepts has been done, based upon which the scientificalness and applicability of them are discussed in this study. Regarding the method on the analysis of the pore water pressure distribution, especially on the analysis of reduction of the pore water pressure, the classical seepage methods based on seepage law and effective stress theory are commented first, and at the same time, the current methods in heat discussion based on the bound water theory are also generalized, the applicability of the two methods on the pore water pressure above are analyzed respectively, and some suggestions are made. In the aspect of the prediction of the highest forward groundwater level in the future, three major methods (ie. the method of historical highest groundwater level, a method of inversion based on the macro data and a numerical method)are discussed, whose advantages, problems and something to be improved are discussed. In the aspect of the technique systems of the GWLAF, it is discussed briefly, taking Beijing as an example. Finally, commenting the researches on the GWLAF in China, and considering China's national conditions, the progress and suggestions for the future research are made.