The present invention relates to an insulating composition for a substrate including a soluble liquid crystal thermosetting oligomer, a metal alkoxide, a graphene oxide, and a short fiber, and an insulating material and a substrate using the same. The insulating composition in accordance with the present invention can effectively reduce the coefficient of thermal expansion by the addition of the metal alkoxide and the graphene oxide. Therefore, it is possible to provide a substrate material with greatly increased strength and rigidity by the addition of the short fiber as well as to manufacture a substrate with improved thermal stability by using the insulating composition in accordance with the present invention as an insulating material of the substrate to minimize dimensional deformation due to heat.