China holds this grand celebrations every 10 years to commemorate revolutionary leader Mao Zedong's proclamation for founding the People's Republic of China on October 1, 1949.
President Hu Jintao was to deliver a speech at the historic square to an invitation-only audience of spectators and foreign dignitaries, with security air-tight across the city.
This celebration also emphasizes that China has re-emerged as an undeniable force in the world.
"In another 40 years, the 100th anniversary of our nation's founding will come. At that time, a prosperous, powerful, democratic, civilised, harmonious and advanced socialist nation will tower over the East," China's premier Wen Jiabao said on Wednesday, Sep 30.
Police have for weeks been checking traffic entering the capital and even the city's airport will shut for the parade's three-hour duration.
Beggars and the homeless have been cleared out and knife sales temporarily banned in some stores after two recent stabbings near Tiananmen Square.