Abstract: As a dynamic process, urban system develops through actions of exogenous and endogenous actors. Transnational institutions are significant exogenous actors, whose critical efforts for urban globalization deserves more attentions. In the case of Bonn, institutional milieu and situation is created by the power and policies of the federal, state and local government, which is indispensable for embedding of transnational actors. Under the common appeal of establishing international cooperation with government, companies, local people and also non-human actors, transnational institutions such as UN institutions, NGOs, science and research institutions have settled down in Bonn with positive translation and produced interactive effect with them, which creates firmly "seamless" actor network for urban development of globalization. Different intentions and behavioral patterns also reshape urban space, which becomes the way to investigate maturity of the actor network in Bonn. In fact, Bonn has experienced: (1) spatial reconstruction from politics to international cooperation; (2) spatial agglomeration with hub-spoke model. UN institutions as hubs and others diffuse regularly; (3) at first, resources, information and locations of actors are diverse, which shapes unequal power space through the operation of network hubs; With the process of rejection, conflict, negotiation and accordance at last, urban spatial function advances with progressive maturity of the actor network. Through establishing theoretical connection between ANT and urban study while combining transnational institutions within urban globalization research, on the one hand it is broadening the approach of urban study, on the other hand it is also the way to explore more through the interaction of multi-actors during the urban development process of globalization.

Key words: transnational institutions, actor network theory (ANT), Bonn, urban globalization