Hengqin island of Guangdong is located at the junction of China mainland， Hong Kong and Macao， which is the third national level new area. The general idea and development objectives of construction planning for Hengqin new area（HNA） smart grid project is introduced， and the technical characteristics and contents， including the intelligent operation center， on-line monitoring of terminal units， distribution automation， distributed energy resources and vehicle-to-grid， home management system， data acquisition for power consumption and demand side management are presented. The influence factors for smart grid reliability and the supporting measures to enhance the reliability are also analyzed.This work is supported by Major Science and Technology Program of China Southern Power Grid Co. Ltd.（No. K-GD2011-420）.