The Forbidden City is located in the center of Beijing. As the imperial palace for two dynasties, it is the essence of Chinese palace and masterpiece of Chinese old buildings. When upgrading from analog system to digital and HD system, the Forbidden City used Zhejiang Uniview Technologies Co., Ltd. surveillance platform. New HD digital surveillance subsystem seamless integrated into original analog system. It managed and presented both two systems together, protected previous investment and laid a solid foundation for a whole HD digital system in the future.