The historic constitutional amendment cleared the rubber-stamp parliament with 2,958 in favour, two against, three abstentions and one invalid vote, despite an unusual bout of online criticism that censors have scrambled to extinguish.
The ballot, which was largely symbolic, came two weeks after Communist Party-controlled media announced the proposal.
But "Xi Dada" ("Big Uncle Xi"), as he has been dubbed by Communist propaganda, has broken sharply with that tradition since taking over as president in 2013 and now looms over the country in a deepening cult of personality.
Inside Beijing's Great Hall of the People, almost 3,000 delegates to the National People's Congress (NPC) today cast their ballots on a series of proposed amendments - including removing the restriction that had limited the presidency to two consecutive five-year terms.
"It means that Xi is now unquestionably a Leninist strongman", Steve Tsang, director of the China Institute at SOAS University of London.
"The Constitution was also updated to state that the leadership of the Communist Party of China is the defining feature of socialism with Chinese characteristics". The main, no doubt, is elimination of limits to presidential errands that Deng Xiaoping had introduced in his day to institutionalize power and avoid Mao's personalism. China's supreme law was last amended in 2004.
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The amendments also include inserting Xi's political theory into the constitution, something that was already done for the party constitution in October, and clauses to give a legal framework to a new super anti-corruption department.
The party later disclosed that Xi had presided over a meeting of the Politburo in September during which the leadership made a decision to revise the constitution.
For India, observers say, Xi's continuation will have particular significance, especially in the backdrop of last year's 73-day-long Dokalam standoff where Chinese troops tried to build a road in the area claimed by Bhutan to reach close to India's narrow corridor connecting its northeastern states. Now he must deliver, experts said. The central committee had also proposed listing the National Supervisory Commission as a new organ in the Chinese Constitution.
"That doesn't bode well for hard reforms ahead: Will the CCP be able to raise the retirement age?" The constitution had until now limited presidents to serving only two consecutive terms. A total of 2,964 votes were cast.
"This shows he has now narrowed the scope of internal policy debates so much that no one dared to counsel him", he said by email.
"The people's government must never forget the word the "people" and we must do everything we can to serve the people, but to get all the government officials to do this is not easy, in some places this is not done very well and in other places it is done very badly", Xi told AFP.
At the time, Xi vowed to root out corruption following a $10 billion smuggling scandal, but ruled out political reform to confront the problem, saying he would work within the one-party structure and system of political consultation and "supervision by the masses".
An oath-taking ceremony will be arranged at the ongoing NPC session for the newly elected or appointed leaders and officials, he said.