The encountered difficulties that prevent ZnO nanowires from being used as light-emitters are p-type doping and quantum well (QW) integration. The growth of homogenous nanowire quantum wells is usually influenced by the shadowing effect associated with nanowire growth density. In this paper, based on the growth density control of nanowire array, a new two-step pulsed laser deposition (PLD) strategy was demonstrated to grow two kinds of ZnO nanowire QWs, e.g. radial nonpolar QW and axial polar QW. The growth-density control of ZnO nanowires was realised by introducing a wetting layer and adjusting the substrate-target distances. The structural and optical characterizations of these two kinds of nanowire QWs prove that the radial nanowire QWs are more homogenous than axial QWs, which also show better optical properties.