The analysis of foraminiferal B/Ca ratios is a greatly potential and widely concerned paleoceanographic method, which is applicable to the reconstruction of  the past pH and CO^2-₃  concentrations of sea water, and under certain situations also can also be used to reflect the changes of the atmospheric CO₂ concentration from surface water, and indicate changes of ocean current and water mass of deep water. Compared with the conventional method of boron isotopes, the B/Ca ratio method is relatively easier, more stable, and less  affected less by dissolution and postdeposition alternations. As a result, it is relatively suitable for highresolution paleoceanographic studies. However, this method is comparably new. The foraminiferal biological processes to absorb boron element is still not very clear. Moreover, the mechanisms using B/Ca ratio to reconstruct pH and CO^2-₃  concentrations is not well accepted. As the method is constructed on the basis of empirical function, establishment of its theoretical basis will be the future and important development of this method.