The growth of nanocrystals is a rich field of research that needs progress in the theories and experiments. Further studies on the microscopic growth behaviors via the OA mechanism will help us to understand the crystallization process and control the development of structures. Exploitation of more powerful facilities may capture the real and in situ dynamic information. Alternatively, molecular simulation will provide the proper explanation on the molecular scale, as the OA-based growth process often fails to be directly observed, such as the adsorption and desorption of molecular, the collision mode and process, and bonding.