The dispersibility of hexagonal boron nitride (hBN) particles in epoxy resin with different chemical structures, such as bisphenol and naphthalene, was investigated. The viscosities of hBN slurries changed considerably depending on the diol compound chemical structures. Sedimentation testing of the hBN slurries revealed that the hBN particles in slurries containing naphthalene structures were densely packed due to improved dispersibility of hBN, while the hBN particles in slurries containing bisphenol structures were aggregated. These results suggested that the pi-pi interaction was more dominant in the dispersion of hBN particles than the hydrophobic interaction. Furthermore, the naphthalene type epoxy resin was more effective in improving the dispersibility of hBN as compared to bisphenol A type epoxy resin. The interaction between the basal plane of hBN particles and the chemical structure in the matrix is very important for hBN dispersibility improvement. [GRAPHICS] .