Xi, 59, who succeeded outgoing President Hu Jintao as party secretary-general, and Vice Premier Li Keqiang, 57, who took over from Premier Wen Jiabao, and the other members of the new team make up the Politburo Standing Committee, the power elite in China and its party's highest authority that will lead the country over the next decade.
The new team, described by the official Xinhua News Agency as the "top leaders of the Communist Party of China," appeared before both Chinese and foreign reporters in the Great Hall of the People in Beijing.
The Standing Committee's strength was reduced to seven from nine.
Xinhua, announcing Xi's elevation as general secretary of the party, said other members elected to the Standing Committee included Li Keqiang, Zhang Dejiang, Yu Zhengsheng, Liu Yunshan, Wang Qishan, and Zhang Gaoli.
Their presentation marked the culmination of the weeklong party convention, which is held once every five years, with this year's event also charged with making the once-in-a-decade leadership transition. The Communist Party has ruled the country since 1949 under a one-party system.
The new leaders' meeting with the media was broadcast live on Chinese television and radio as well as online, Xinhua said.
Xinhua separately published the names of all of the 205 members of the Central Committee, elected earlier through secret balloting by the delegates attending the party congress, as well as the 171 alternate members of the committee.
The new team will take over in March when the Chinese Parliament convenes.
Speaking earlier at the closing session of the Congress Wednesday, Hu said: "The congress elected a new central committee of the Party and replaced older leaders with younger ones.
"We are convinced that all the decisions and plans adopted and all the achievements made at the congress, which are of major current and far-reaching historical significance, will play an important role in guiding the all-around development of the great cause of socialism with Chinese characteristics and the great new undertaking of Party building."
In his keynote address at the opening session of the congress, Hu had specifically warned about the country's rampant corruption, which he said could undermine both the party and the state if not checked.
Xinhua said the five-yearly congress was held "at the decisive stage of completing the building of a moderately prosperous society in all respects."
Besides corruption, the new leadership must tackle a host of China's challenges including a slowing economy after years of double-digit growth that made China the world's second-largest economy behind the United States, widening income disparity among the country's 1.3 billion people, and rising ethnic tensions witnessed by the recent spate of self-immolations by Tibetans protesting Chinese rule of their land, while pushing ahead with political and economic reforms.