The high-level meeting, chaired by President Hu Jintao, was attended by the party's top 270 leaders, a party communique carried by Xinhua news agency said.
China's parliament, the National People's Congress, is expected to formally pass the personnel changes and reform and restructuring plans when it meets for its annual 10-day session starting Wednesday next week.
Although no specifics were released, Hu is widely expected to be re elected as president by the congress to a second five-year term, while Wen Jiabao will remain prime minister.
The party also Wednesday approved of an administrative reform plan to be gradually completed by 2020 which will bring the nation's political reform in line with its huge economic advances over the last two decades, the communique said.
"As we enter a new phase of our nation's economic and social development and face the new demands to safeguard people's democratic rights and uphold social fairness and justice, there are still some areas in our nation's political system that lag behind and need further improvement," it said.
The party also approved a reform of the State Council, China's Cabinet, it said. The reform is likely to cut the number of government ministries to 21, state media reports said.
Meanwhile a series of lower-level appointments is expected to be approved by the parliament, which may hint at China's future leaders.
Although Xinhua did not report the names on the election lists approved by the meeting, former Shanghai party chief Xi Jinping, 54, is widely expected to be named as vice president, securing his place as Hu's successor as party head in 2012 and president in 2013.
Li Keqiang, 52, is expected to win one of the vice premierships as the top candidate to replace Wen in 2013. Li, former communist party boss of northeastern Liaoning province, is seen as closely allied to President Hu.
Both Xi and Li were named to the elite nine-member standing committee of the Communist Party's Politburo during a key party congress in October last year, when they emerged at the head of the next generation of Chinese leadership.
