A new strategy for precisely controlling the growth of heterostructured nanocrystals through a dissolution-attachment process of core-shell nanocrystals is proposed. The secondary growth process of Cu-Au bimetallic nanocrystals (BNCs) comprising of a core-shell structure has been systematically investigated, which generates a variety of heterostructured Cu-Au-based nanocrystals. Various factors such as the addition of dodecanethiol and the size of the Cu-Au nanoseeds that contribute to the diverse growth of core-shell Cu-Au BNCs have been examined. A dissolution-attachment growth process is suggested on the basis of UV-vis and transmission electron microscopy measurements. In addition to the size, the shape and composition of the final nanocrystals could be controlled by this process. This new strategy will allow us to control the growth process of heterostructured nanocrystals independently from the nucleation stage, which might become much more complex than that of the single-component nanocrystals.