Calcium carbonate (CaCO3) particles with different morphologies and polymorphs were obtained in the presence of p-aminobenzene sulfonic acid anhydrous-L-Lysine (L-Lys) complexes. The samples were characterized by XRD. FT-IR, and SEM. The ratio of the surfactants, experimental system pH value, and the Ca2+ concentration were found to play an important role not only in the morphologies but also in polymorph of calcium carbonate product. Moreover, the possible formation mechanism of these microstructures has been proposed. (C) 2010 Elsevier B.V. All rights reserved.