This article introduces the fundamental principal nanopiezotronics which utilizes the coupled piezoelectric and semiconducting properties of nanowires and nanobelts for designing and fabricating electronic devices and components, such as field effect transistors and diodes. The physics of nanopiezotronics is based on the principle of a nanowire nanogenerator that converts mechanical energy into electric energy. It is anticipated to have a wide range of applications in electromechanical coupled electronics, sensing, harvesting/recycling energy from the environment, and self-powered nanosystems.