Single GaAs/Al0.5Ga0.5As V-grooved quantum wire modified by selective ion-implantation and rapid thermally annealing was investigated by spatially-resolved microphotoluminescence and magneto-resistance measurement. Spatially-resolved photoluminescence results indicate that the ion-implantation induced quantum well intermixing raises significantly the electron subband energies of the side quantum wells and vertical quantum wells, and more efficient accumulation of electrons in the quantum wires is achieved. Furthermore, the polarization properties of the photoluminescence from the quantum wires show large linear polarization degree up to 63%. Magneto- transport investigation on the ion implanted quantum wire samples presents the quasi-one dimensional intrinsic motion of electrons, which is important for the design and optimization of one dimensional electronic devices. Single GaAs / Al0.5Ga0.5As V-grooved quantum wire modified by selective ion-implantation and rapid thermally annealing was investigated by spatially-resolved microphotoluminescence and magneto-resistance measurement. Spatially-resolved photoluminescence results that the ion-implantation induced quantum well intermixing raises significantly the electron subband energies of the quantum quantum wells and vertical quantum wells, and more efficient accumulation of electrons in the quantum wires is achieved. Furthermore, the polarization properties of the photoluminescence from the quantum wires show large linear polarization degree up to 63 %. Magneto-transport investigation on the ion implanted quantum wire samples presents the quasi-one dimensional intrinsic motion of electrons, which is important for the design and optimization of one dimensional electronic devices.