GaN nanobelts are synthesized using the chemical vapor deposition method with the catalyst of Ni.The microstructure,composition and photoluminescence property are characterized by x-ray diffraction,field emission scanning electron microscopy,high-resolution transmission electron microscopy and photoluminescence spectra.The results demonstrate that the single crystalline GaN nanobelts are grown with a hexagonal wurtzite structure,in width ranging from 500nm to 2μm and length up to l0-20μm.Moreover,a large piezoelectric coefficient d33of 20pm/V is obtained from GaN nanobelts by an atomic force microscopy and the high piezoelectric property implies that the perfect single crystallinity and the freedom of dislocation for the GaN nanobelt have significant impact on the electromechanical response.