With no doubt，the Keyword of City theories and practices in 2015 shall be innovation. Innovation transforms itself from one of the policy choices in fighting against the New Great Recession since 2008 to the only strategy in positioning a city in the new round of world city network formation. The paper provides a full introduction of the concept，characters as well as functions of International Innovation hub. The authors believe that the “World City 2.0” Index developed by this annual report indicates the path leading to the formation of International Innovation hubs.