Recent works mainly in our laboratory on the kinetic study of the colloidal crystallization, structural and dynamic properties and the electro-optic effects of colloidal crystals have been reviewed. Crystal structure and the giant size of single crystals are formed in the diluted and highly deionized suspensions of colloidal spheres. Nucleation and crystal growing processes in colloidal crystallization are studied using the techniques of static and dynamic light-scattering and the reflection spectroscopy. Importance of the intersphere repulsion and the synchronous fluctuation are supported in the crystallization processes. Retardation in the nucleation and growing rates is observed from the micro-gravity experiments using parabolic flights of an air-craft. Dynamic character of colloidal crystals, liquids, and gases are discussed from the dynamic light-scattering data. One, two and three dynamic modes are observed for colloidal crystals, liquids and gases, respectively. Furthermore, electro-optic properties such as modulation effects (phase delay, harmonics, transformation in wave forms, etc.) and acoustic shear waves have been clarified for the colloidal crystals.