Abstract: The situation in the construction of national continuous operational reference systems (CORS) in Europe, America, and intercontinental CORS is introduced, especially the state of art and their enlightenment are analyzed. The concepts of national CORS and nationwide cooperative CORS are also given. At the same time, the recommendation is made to form the state level CORS network from national CORS and nationwide cooperative CORS on certain condition and make related standards to operate and manage. The prime goal of national CORS and state level CORS is to update and maintain the China geodetic coordinate system (CGCS2000). That is to say, to realize the CGCS2000 mainly on the maintenance of national CORS network. On this basis, the goal and scheme to adopt CORS to update CGCS2000 are proposed. As to the establishment of regional CORS, the concepts of frame network and datum network are introduced, which are applied in the establishment of regional geocentric, dynamical reference frame, and the connection between national coordinate system and local mapping coordinate system, respectively. And the mode of establishment local geocentric, dynamic reference frame are also given.