The Biggest World Expo In Shanghai - Shanghai celebrated the opening of the 2010 World Expo on 1st May with a lavish display of fireworks, fountains and laser lights. Chinese President Hu Jintao officially opened the expo at a ceremony. The event showcased China's growing economic and geopolitical sway. At least 70 million visitors, almost all of them Chinese were expected to visit pavilions and exhibitions staged by more than 240 countries and organizations from around the world.