Two pyridine-containing triphenylbenzene derivatives of 1,3,5-tri(m-pyrid-3-yl-phenyl)benzene (TpPyPB) and 1,3,5-tri(p-pyrid-3-yl-phenyl) benzene (TpPyPB) (see figure) with high electron mobility and high triplet energy level are designed and synthesized. Highly efficient blue and green phosphorescent OLEDs are achieved by using TmPyPB and TpPyPB as an electron-transport layer, respectively.