President Xi Jinping announced on Thursday he would cut troop levels by 300,000 as China held its biggest display of military might in a parade to commemorate victory over Japan in World War Two, an event shunned by most Western leaders.
China's confidence in its armed forces and growing military assertiveness, especially in the disputed South China Sea, has rattled the region and drawn criticism from Washington.
Xi, speaking on a rostrum overlooking Beijing's Tiananmen Square before the parade began, said China would cut by 13 percent one of the world's biggest militaries, currently 2.3-million strong.
He gave no time frame for a reduction that is likely part of long-mooted military reforms. Troop numbers have been cut three times since the 1980s as part of China's efforts to modernize its armed forces.
"Prejudice and discrimination, hatred and war can only cause disaster and pain," Xi said. "China will always uphold the path of peaceful development."
He then descended to Beijing's main thoroughfare and inspected rows of troops, riding past them in a black limousine and bellowing repeatedly: "Hello comrades, hard-working comrades!"
More than 12,000 soldiers, mostly Chinese but with contingents from Russia and elsewhere, then began marching down Changan Avenue, led by veterans of World War Two carried in vehicles.
They were followed by ballistic missiles, tanks and armored vehicles, many never seen in public before. Advanced fighter jets and bombers flew overhead in a highly-choreographed spectacle that lasted around 90 minutes.
Among the weapons China unveiled for the first time was an anti-ship ballistic missile, the Dongfeng-21D, which is reportedly capable of destroying an aircraft carrier with one hit.
Also shown were several intercontinental ballistic missiles such as the DF-5B and the DF-31A as well as the DF-26 intermediate range ballistic missile (IRBM), dubbed the "Guam killer" in reference to a U.S. Pacific Ocean base.
For Xi, the parade is a welcome distraction from the country's plunging stock markets, slowing economy and recent blasts at a chemical warehouse that killed at least 160 people.
Xi was joined by Russian President Vladimir Putin and leaders of several other nations with close ties to China, including Sudanese President Omar Hassan al-Bashir, who is wanted for war crimes by the International Criminal Court.
Most Western leaders rebuffed invitations to attend, diplomats said, unhappy about the guest list and wary of the message China would send with the show of strength.