Tanks, hypersonic ballistic missiles capable of reaching the US, formations of goose-stepping troops and a formation of fighter jets trailing coloured smoke were all on display as the country flexed its military muscles.
Dressed in a “Mao”-style slate grey suit and, in a display of Communist party unity, flanked by his predecessors Hu Jintao and Jiang Zemin, Mr Xi gave an address from the Gate of Heavenly Peace, the same spot where Mao Zedong proclaimed the founding of the People's Republic of China on this day in 1949.
“No force can ever shake the status of China, or stop the Chinese people and nation from marching forward,” Mr Xi said.
China is using this year’s National Day to proclaim its confidence on the global stage. But it is also nervous about threats to the Communist Party’s grip on power, last week warning that the nation would “crumble” if it was not ruled with a firm hand.
The crowd that Mr Xi addressed was carefully vetted, and members of the public trying to access Tiananmen Square on the day were turned away. People with houses lining the parade route were told not to look out of their windows.
As the parade gathered in the square, Mr Xi descended to street level and inspected row upon row of gleaming military hardware. Riding in a black limousine he shouted: “Hello comrades”, to replies from the soldiers of “Follow the Party! Fight to win! Forge exemplary conduct!”
The event highlighted rapidly developing Chinese weapons technology that foreign analysts say is close to matching the US, Russia and Europe in missiles, drones and some other fields.
China’s campaign of military modernisation has alarmed its neighbours in the region, not least because Beijing lays claim to the entirety of the contested South China Sea, as well as independently-run Taiwan and some Japanese islands.
One of the most closely-watched weapons unveiled Tuesday was the Dongfeng-17, a nuclear-capable glider that foreign analysts say is designed to manoeuvre at high speed to evade anti-missile defences.
Another missile displayed, the Dongfeng-41, is believed to have a range of up to 15,000km (9,400 miles), which would make it world's longest-range military missile. Analysts say it may be able to carry as many as 10 warheads to hit separate targets.
The People’s Liberation Army (PLA), the world's biggest military with 2 million men and women in uniform, also had the world's second-highest military spending at an estimated $250bn last year, according to the Stockholm International Peace Research Institute. The US, with a force of 1.3 million people, led in spending at $650bn.
China has about 280 nuclear warheads, compared with 6,450 for the United States and 6,850 for Russia, according to SIPRI. Beijing says it wants a "minimum credible nuclear deterrent" but won't be the first to use atomic weapons in a conflict.
And Mr Xi also emphasised China’s commitment to “firmly uphold world peace”, saying that the country would pursue a mutually beneficial strategy of opening up.
After the military aspect of the parade was complete, 70,000 balloons and 70,000 doves - symbolising peace - were released into the smoggy Beijing air. A large fireworks display is planned for the evening.