The micro-photoluminescence(mu-PL) scan has been performed on a single V-groove GaAs/AlGaAs quantum wire in the direction perpendicular to the wire. The variation of mu-PL spectra from various quantum structures with different spatial positions has been observed. In the region of quantum wire (QWR) the PL spectra contain the peaks from QWR, necking quantum well (NQWL) and vertical quantum well (VQWL),while in the area about 1 mu m and farther away from the QWR the PL spectra show the peaks from side-wall quantum well (SQWL) and top quantum well (TQWL). All the scanned PL spectra have been fitted by Gauss line shape. The asymmetric PL peaks of QWR and SQWL were decomposed into two components which were ascribed to the optical transitions between the electron ground state in the conduction band and the heavy hole and the light hole ground states in the valence band. The variation of PL intensity from luminescent components with the spatial positions directly demonstrates the origin of the photoluminescence relating to different quantum structures, and reflects the carrier transfer from SQWL to QWR, resulting in the PL quenching of SQWL.