The growth mechanism of shape-selected synthesis of nanocrystals in all systems can be attributed to an oriented surface assembly process of growth units, in the present of additives or not. In this article, we present an example displaying the influence of the surface reconstruction process of nuclei on the shape-selected growth behaviors of inorganic nanocrystals. The basic principle lies in the sufficient diffusion of growth units on crystal surfaces according to Kossel's growth model. Shape-controlled octahedral and truncated octahedral crystals of zinc tin oxide (ZTO) were successfully synthesized by pretreating precursors at room temperature without any surfactants. And, the method can be applied to CaSn(OH)(6), SrSn(OH)(6), and ZnO. We also found out that there is a linear correlativity between the truncated degrees and the amount of NaOH when studying morphological evolution behavior from an octahedron to a cube of ZTO.