In this study, aluminum nitride (h-AlN) nanotubes with high crystallinity and yield have been prepared by AlP and NaN3 in a stainless steel autoclave at 350 °C. The samples were studied by powder X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and HRTEM in detail. The lengths of the AlN nanotubes are about 1 μm with most of the tube ends are open. The AlN nanotube preferentially grow along the [001] direction. The results demonstrate that the bending and roll-up of a thin layer to form tubular nanoscrolls is a thermally driven process. One-dimensional preferential growth was explained in terms of the crystallographic feature of hexagonal AlN.