The effect of hydroxylation of barium titanate (BaTiO3) on the rheological behaviors of the corresponding aqueous suspensions in the presence of poly(vinyl alcohol) (PVA) and boron oxide (B2O3) was investigated. Without using hydroxylated BaTiO3, the gelation between PVA and B2O3 caused the aqueous BaTiO3 suspension to form a three-dimensional gel-like structure, resulting in a poorly dispersed and dilatant suspension. Interestingly, using hydroxylated BaTiO3 significantly improved the rheology of aqueous suspensions. The reason for the improved rheological behaviors is that the hydroxylated BaTiO3 specifically interacts with the PVA and B2O3, and thus the PVA has a diminished opportunity to gel with the B2O3.