Zinc-blende GaP nanocrystals were treated with different methods. It was found that part of the nanocrystals transferred irreversibly into four new phases of GaP nanocrystals with different lattice constants and the largest one is about 1.3 times of the literature data, which was characterized by X-ray diffraction, transmission electron microscopy. (C) 2002 Elsevier Science B.V. All rights reserved.