The formation of self-organized flower-like structures of copper hydroxide hydrate on copper foils was studied in mixed electrolytes of water and amides. The morphology of crystals deposited on copper foil changed with the formamide (FA) concentration. For mixed electrolytes of 6:4 and 5:5 of H2
O:FA v/v, flower-like crystals consisting of nanosheets were deposited on the copper surface within a week. When immersed in 8:2 H2
O:FA v/v, nanosheets were formed mainly on the copper surface. For the most concentrated solution of 3:7 H2
O:FA v/v in this experiment, rectangular crystals were deposited without morphological control, forming rock-like structures. XRD patterns revealed crystals composed of Cu(OH)2
O. UV-Vis absorption spectra of FA solutions suggest that complexes of [Cu(HCONH2
, x=0～3, are formed in mixed electrolytes of water and FA according to the solution composition. Acetamide(AA) and N
-dimethylformamide(DMF) were also examined. Flower-like structures were observed in AA aqueous solution, although the structures required 3 weeks to form. No change of copper foil surface morphology was observed in mixed electrolytes of water and DMF with copper foils during 3 weeks. These deposition rates of flower-like structures correspond to the concentrations of eluted Cu2+
ions in solutions in the following order: FA>AA>DMF.