Graphene/carbon-nanotube (CNT) hybrid material can be useful in energy storage and nanoelectronic technologies. Here we address the CNT-oscillator encapsulated in a graphenenanoribbon (GNR) trench as a novel design, and investigate its properties via classical molecular dynamics simulations. Since the energy barrier was very low while the CNT was encapsulated in the GNR trench, the CNT absorbed on the GNR surface could easily be encapsulated in the GNR trench.MD simulations showed that the CNT oscillator encapsulated in a GNR trench is compatible with simple CNT oscillators, so we anticipate that the CNT in GNR trench could work as an oscillator. So we can anticipate that the CNT encapsulated in a GNR trench can be applied to ultra-sensitive nanoelectromechanical oscillators, and this system has the possibility to be applied to relay-switching devices, and to shuttle memory.