Expo 2010, officially Expo 2010 Shanghai China is being held on both banks of the Huangpu River in the city of Shanghai, China, from May 1 to October 31, 2010. It is a World Expo in the tradition of international fairs and expositions. The theme of the exposition is "Better City – Better Life" and signifies Shanghai's new status in the 21st century as the "next great world city". It is the most expensive Expo in the history of the world's fairs. The Shanghai World Expo is also the largest World's Fair site ever at 5.28 square km.
More than 190 countries and more than 50 international organizations have registered to participate in the Shanghai World Expo, the largest ever. China expects to receive almost 100 foreign leaders and millions of people from across the world to come and visit the World Expo. More than 70–100 million visitors are expected to visit the expo, which would make it the most visited in history.
http://en.wikipedia.org/wiki/Expo_2010