Each XRD peak intensity of CaSO4 center dot 2H(2)O crystals changes according to their morphologies. This research clarifies the relationship between XRD peak intensity and morphologies on CaSO4 center dot 2H(2)O crystals synthesized by reaction crystallization with various additives. As a result, as XRD relative intensity of (021) face increases, average longitude and aspect ratio decrease and needle-like or plate-like large crystals transform into granular microcrystals. (C) 2013 The Authors. Published by Elsevier By. All rights reserved.