Global value chain:a new perspective of global urban network researches

City network is the paradigm of urban space,and it can be divided into the world city network and regional city network in spatial scale.The researches on world city network have experienced three development stages: world city,world city hierarchy and the world city network.Regional city network researches include the mega-cities area,global city regions,urban agglomeration and other research groups.The world city network which uses advanced producer services analysis is a single central city model and separated with regional city network which is a closed model.Two spatial patterns can't reasonably explain the contemporary world city system and the inherent relationship between themselves.Global value chains can effectively integrate the world city network and regional city network and will be an analysis tool for studying multi-city model of the world city network which is a composite of different functions cities.