Calcium carbonate/bovine serum albumin (CaCO3/BSA) hybrid crystals with flying-plate shape have been successfully synthesized at ambient temperature. The products have been characterized by X-ray powder diffraction (XRD), HRTEM-SAED, EDS, field-emission scanning electron microscope (FE-SEM), thermogravimetry-differential thermal analyses (TG-DTA), FT-IR, photoluminescence (PL) and circular dichroism (CD) spectroscopy. The results of the research showed that the as-prepared CaCO3/BSA hybrid crystals with sizes about 1 mu m in diameter were self-assembled by nanoparticles. Furthermore, the interactions between CaCO3 and BSA were studied at supramolecular level and an interesting mechanism about the formation of the CaCO3/BSA hybrid crystals was discussed. (C) 2009 Elsevier B.V. All rights reserved.