Calcium carbonate deposited on titanium substrate by electrochemical method has been investigated from view point of modification and shape. Electrolytic solution of calcium dihydrogencarbonate was prepared by bubbling carbon dioxide into calcium carbonate suspension. Calcium carbonate was deposited on the substrate electrode in the electrolytic solution of pH1.99-8.29. Main product obtained at lower pH region was calcite of rhombohedral shape and that obtained at higher pH region was vaterite of spherical aggregate of plate-like crystal. The larger the current density and the longer the electrolysis time were, the larger the deposition rate of vaterite became. The tendency was estimated to be related to the hydroxyl ion concentration on the substrate electrode surface.
