As research continues, the control on the polymorph and morphology of calcium carbonate (CaCO3) becomes a hot topic because its application is limited by these parameters. The assemblage of nano-CaCO3 particles on palmitic acid template was successfully realized in the carbonation of calcium hydroxide (Ca(OH)(2)) slurry. The polymorph and morphology of CaCO3 particles were investigated by XRD and TEM, respectively, and the interaction between palmitic acid and CaCO3 particles was studied by FTIR. It reveals that the amount of palmitic acid does not change the crystalline phase of CaCO3 particles. However, the morphology of CaCO3, from nano-cubic single particle to micro rod-like aggregation, can be controlled by varying the amount of palmitic acid. The assemblage of CaCO3 particles is discussed from the view of the deformation of the micelle when it is absorbed on the Ca(OH)(2) particles and of the aggregation of extremely small CaCO3 particles under the driving force of high surface energy. (C) 2013 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.