In(OH)3 and InOOH crystals were synthesized at different temperatures by diglycol-mediated solvothermal processes. Their phase structures, morphologies and growth mechanisms were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and chemical analysis. A small quantity of ((H2O)3In)Cl3 was observed in In(OH)3 crystals, which resulted in formation of In(OH)3 crystals with complicated shapes and morphologies. In(OH)3 grew along [1 0 0] direction, while ((H2O)3In)Cl3 grew preferentially along several crystal directi...