The parade comes just two days after the Shanghai Cooperation Organisation (SCO) Summit, also attended by Putin, concluded in northern China's Tianjin.
Visuals from the parade, marking 80 years since Japan's defeat in World War II, showed Xi, Putin and Kim together on the frontlines. The three leaders were seen on the Tiananmen Gate Tower as Chinese soldiers fired a gun salute and carried out a flag-raising ceremony.
After a photo-op, three leaders walked further inside the parade venue, talking and sharing some laughs with each other.
Xi, Putin and Kim, with smiling faces, were also seen greeting the Chinese military veterans seated at the parade venue ahead.
Several other heads of state and government, including those from Pakistan, Vietnam, Malaysia, Iran, Serbia, Belarus and Slovakia, were also present at the parade.
At the parade, China showcased its latest anti-ship missiles, combat drones and nuclear-capable ballistic missiles.
The new weapons with the latest technology, including hypersonic systems, are developed with an intent to suppress the US Navy in the Western Pacific, Bloomberg reported, citing Tianran Xu, a senior analyst for Open Nuclear Network security think tank.
"With huge national sacrifice, the Chinese people made major contributions to saving human civilisation and safeguarding world peace," Xi said in his speech at the event. He also paid tribute to the Chinese veterans and those who contributed to the victory against Japanese aggression.
Earlier on Tuesday, Putin and Xi held talks, affirming close ties between China and Russia. The Chinese President called Putin an "old friend" and said that relations between their countries have "withstood the test of changing international circumstances".
Putin also thanked Xi and affirmed that their ties were now at "an unprecedentedly high level".
Meanwhile, North Korean leader Kim Jong Un's visit to China marks his debut on a multilateral diplomatic stage since taking power 14 years ago.