Recently, nanomaterials have drawn interests owing to their special characteristics which differ from bulk crystals.1-7 The synthesis of colloidal inorganic nanocrystals especially with respect to the control of their shape, however, is under developed and still complicated. Since novel properties of nanomaterials depend on their size and shape, a new direction for synthetic methods and an understanding of the mechanisms by which the size and shape of the nanocrystals can be easily varied are key issues in nanochemistry