A relation between the orientation of lattice plane of blue phase (BP) and the surface free energy of the solid substrate contacting with BP was investigated. The surface of substrates were coated by a polyimde or treated by a silane coupling reagent. The planes of lattice were identified from the optical texture and the reflection spectra of BP I sandwiched between the two substrate surface. As a result, we confirmed that the orientation of lattice plane was closely related to the surface free energy of the substrate. In particular, the area fraction of the lattice plane (110) of BPI increased as the polar component of surface free energy decreased. The value of surface free energy of the substrate is suggested to be one of the important factors to control the lattice plane of BP.