Pd nanoparticles were supported on the surface of g-C3N4 by a facile method assisted by ultrasonication. The Pd/g-C3N4 catalyst was characterized by N-2-adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The XRD and TEM analyses reveal that the Pd nanoparticles are evenly distributed on the surface of g-C3N4 with an average size of 4 nm. The XPS results indicate that the Pd interacts with the N of g-C3N4. The supported catalyst shows high efficiencies in Suzuki-Miyaura reactions with up to 99 % isolated yield under mild reaction conditions. The catalyst can be easily recycled at least 3 times without any loss of activity and selectivity. The excellent performance of the catalyst in activity and reusability may be attributed to the strong interaction between g-C3N4 and Pd nanoparticles, and the robust nature of the CN framework, respectively. [GRAPHICS] .