Semiconductor nanowires (SNWs) show great promises as building blocks for nanoelectronics, optoelectronics and biological or chemical sensors. Due to their quasi-one-dimensional nature, research into the fundamental physical properties of nanowires has focused on quantum size effects, e.g., transverse confinement for electrons or phonons. However, the effects of the shape and surface of nanowires on the physical properties of SNWs have not yet been systematically studied. In this presentation, we will first demonstrate that a diameter (cross section) modulation activates surface optical (SO) phonon Raman scattering. The SO phonon frequency is shown dependent on the surrounding dielectric constants and diameter. The SO Raman band frequencies were quantitatively explained with analytical solutions based on a dielectric continuum model, in which the diameter, cross sectional shape and surrounding dielectric media all should be taken into account. We further demonstrated that the activation of SO phonon Raman scattering involves a symmetry breaking in surface potential along nanowire axis originate from inherent modulation of vapor-liquid-solid (VLS) growth process. Next, we will demonstrate a high mobility one-dimensional electron gas systems based on InAs/InP nanowire heterostructures and their applications in complementary metal-oxide-semiconductor (CMOS) nanoelectronic circuits. We obtained the highest electron mobility and largest scaled ON-current in those field effect transistors (FETs), which represents a significant improvement over other 1D nanostructures (including carbon nanotubes) and planar metal-oxide-semiconductor FETs. Using a contact printing technique and combined with hole gas Ge/Si core-shell heterostructures, 3-dimensional (3D) integrated multi-layer nanowire CMOS circuits have been achieved, which exhibit increased circuit complexity, low static power consumption and faster device switching speed. As an example, CMOS ring oscillator constructed with three CMOS inverter logic gates showed oscillation frequency of 108 MHz, which is the highest switching speed reported up to date utilizing nanomaterials.