Smart distribution network involves distributed generation, micro-grid, electric vehicles, energy storage and other new elements. Besides it has characteristics of bidirectional interactive, network self-healing, power quality improvement, protection of reliability of power supply, elimination on the spot of distributed clean energy and so on. It is currently an important and popular research focus of smart grid. In this paper smart distribution network system architecture was introduced from four aspects, which include planning, operation, management, and integrated application, then different construction modes of smart distribution network were proposed. Finally, the evaluation indicator and methods for smart distribution network construction were discussed.