We report on results of the fabrication and the micro-reflectance measurement of GaN photonic crystals. The etching performance of GaN has been studied with a conventional reactive ion etching system and SiCl4 plasma. We obtained an etch rate of 100 nm/min and etching depth of 600 nm for dense GaN pillars. With graphite lattice of 270 run period we observed a high reflection peak in the region of 400 nm wavelengths, depending strongly on the incident light polarization, which is in a good agreement with the theoretical calculation. (C) 2001 Elsevier Science B.V. All rights reserved.