Blue phase (BP) is an attractive liquid crystal because of the 3-dimensional nano-structure. We have tried to obtain the blue phase by using photocurable mesogenic monomers for nano-structured materials. In this paper, we report the dependence of the BP stability on the materials of mesogenic monomers and chiral dopants. The BP does not appear in a single monomer medium used in this research. The complex interaction between the different kinds of monomers is necessary for the appearance of BP. Furthermore, the important characteristics of chiral dopant are not only the chiral strength.