Non-polar (1 1 (2) over bar 0) GaN has been successfully grown on (0 0 1) LaAlO3 (LAO) substrate by pulsed laser deposition method. The nitrogen plasma is essential to grow pure a-plane GaN films. The insertion of a ZnO buffer layer improves the quality of GaN thin film as shown by X-ray diffraction. Reflection high energy electron diffraction and cross-sectional transmission electron microscopy with selected area diffraction reveal two types of a-plane GaN domains perpendicular to each other in orientation relationships of [0 0 0 1](GaN)parallel to[1 (1) over bar 0](LAO) and [1 (1) over bar 0 0](GaN)parallel to[1 (1) over bar 0](LAO). (C) 2007 Elsevier B.V. All rights reserved.