In this work, we investigated the effect of expandable graphite (EG) on the property of triblock copolymer prepared from a poly(styrene-b-(ethylene-co-butylene)b-styrene) (SEBS) imbibed with an EB-compatible hydrocarbon oil. The rheological properties showed that at a temperature between 30 and 40 degrees C below the gel point, the triblock copolymer gels had a dynamic storage modulus (G') greater than loss modulus (G), thereby indicating that at ambient temperature, a physical network is still present in spite of the addition of nanoparticles. Dynamic rheological measurements of the resultant nanocomposite triblock copolymer gels confirmed that the addition of EG affects the linear viscoelastic properties and maximum operating temperature of the parent triblock copolymer gels. The mechanical properties showed only marginal increase, which can be attributed to the poor dispersion that leads to agglomeration of particle into micrometer size stacks, and thus the particles behave only as inorganic fillers. The morphology and X-ray diffraction revealed that the EG used to generate nanocomposite triblock copolymer gels is dispersed generally within the swollen copolymer and/or solvent.