Chinese President Xi Jinping and Taiwan President Ma Ying-jeou and will address each other as "mister" rather than their usual honorific titles, and will have dinner together after the meeting, China's state-run Xinhua news agency reported, citing Zhang Zhijun, the director of China's Taiwan Affairs Office.
Taiwan's Central News Agency, citing senior government officials, said the two leaders did not expect to sign any agreement, but plan to discuss ways to cement peace.
China and Taiwan -- officially the People's Republic of China and the Republic of China -- separated in 1949 following the Communist victory in the civil war.
But China still considers the island a breakaway province and has warned that a formal declaration of independence could lead to military intervention.
To this day, it's reported to have missiles pointed at the island.
Despite the rift, China is Taiwan's biggest trade partner, hundreds of flights go between the two nations each week and Chinese banks now operate on the island, while some Taiwanese companies have factories in China.
, former head of the Nationalist Kuomintang (KMT) party, has been a key driver in forging closer ties since he came to power in a 2008 election.
Still, major tensions persist -- which is why having the heads of government meet face to face is a big deal.
Massive protests broke out in Taiwan, including students taking over the state's legislative building, over a controversial proposed trade deal with China in 2014. The issue of closer ties with China remains divisive.
On Wednesday, opponents of the meeting gathered outside Taiwan's parliament wielding placards that read: "Don't come back if you go" and "Stop the China-Taiwan relationship."
Ma's former party is struggling ahead of January's presidential election, and Zhang Baohui, professor of political science at Lingnan University in Hong Kong, said that the KMT is using the meeting to reshape the dynamics of the vote.
"Nobody predicted this. It refocuses the voters on cross-strait relations, which always benefits KMT candidates," he said.
Party leaders overwhelmingly voted to change its candidate last month
after polls showed it trailing badly to the main opposition Democratic Progressive Party, which traditionally has maintained Taiwan's political independence from Beijing. Ma can't run due to term limits.
Within China, there's also been resistance to a summit between the two leaders.
"There were apprehensions in Beijing that a meeting with the Taiwanese president might legitimize Taiwan as a sovereign state," said Michael J. Cole, a Taipei-based fellow of the China Policy Institute at the University of Nottingham in the UK.
The United States maintained diplomatic relations with Taiwan until 1979, when it switched recognition to Beijing. But it has maintained unofficial relations with the island since then.
White House spokesman Josh Earnest said it welcomed any steps taken by both sides to try to reduce tensions.