[en] Nanocomposite is proved to be an effective method to improve thermoelectric performance. In the present study, graphene is introduced into p-type skutterudite La_0.8Ti_0.1Ga_0.1Fe₃CoSb₁₂ by plasma-enhanced chemical vapor deposition (PECVD) method to form skutterudite/graphene nanocomposites. It is demonstrated that the graphene has no obvious effect on the electrical conductivity of La_0.8Ti_0.1Ga_0.1Fe₃CoSb₁₂, but the Seebeck coefficient is slightly improved at high temperature, thereby leading to high power factor. Furthermore, due to the enhancement of phonon scattering by the graphene, the lattice thermal conductivity is reduced significantly. Ultimately, the maximum zT value of La_0.8Ti_0.1Ga_0.1Fe₃CoSb₁₂/graphene is higher than that of graphene-free alloy and reaches to 1.0 at 723 K. Such an approach raised by us enriches prospects for future practical application. (paper)