Standing in a black open-roof Red Flag limousine, Xi, also General Secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission, gave the order to Yi Xiaoguang, commander-in-chief of the military parade, to start the review, reports Xinhua news agency.
At the beginning, standing in the limo slowly passing the fluttering flags of the CPC, the nation and the People's Liberation Army (PLA) in Tiananmen Square, Xi watched the flags with full attention and with a salute.
Amid military music played by a military band, the Red Flag limo drove eastward along Chang'an Avenue, which was lined with 15 foot formations and 32 armament formations made up of about 15,000 service men and women as well as 580 pieces of armament.
Xi repeated salutes through microphone: "Salute to you, comrades!" and "Comrades, thanks for your hard work!" The soldiers replied: "Hail to you, Chairman!" and "Serve the people!"
"Follow the Party! Fight to win! Forge exemplary conduct!" the servicemen and women saluted Xi and exclaimed when the limo drove back to Tiananmen Rostrum.
Following this, an air echelon flew over Tiananmen Square escorting flags of the CPC, the nation, and the PLA, marking the start of a grand National Day military parade, deemed to be China's biggest ever.
Each flag was carried by a Z-8B transport helicopter and guarded by two Z-10 armed helicopters on both sides.
Eight Z-10 armed helicopters and 12 Z-19 armed helicopters followed in a formation that spelt "70" in the air.
On the ground, a formation of Guard of Honor marched along the east Chang'an Avenue to Tiananmen Square, holding high the CPC flag, the national flag and the PLA flag.
The Ministry of National Defence has reported that 15,000 military personnel will be taking part, including 59 different elements of the military, while 580 pieces of military equipment will roll through the streets and 160 aircraft will fly overhead.
For the first time, a contingent from China's 8,000-strong UN peacekeeping standby force will also participate.
National Day is celebrated annually to commemorate the establishment of the People's Republic of China on October 1, 1949. It paves the way for a seven-day public holiday called the "golden week".
( With inputs from IANS )