Hu Jintao presided over the closing session.
A total of 2,235 delegates and specially invited delegates to the congress are also expected to pass resolutions on the report of the 16th CPC Central Committee, the work report of the Central Commission for Discipline Inspection and an amendment to the CPC Constitution to embody the "scientific outlook on development" and other major strategic thoughts advanced since 2002.
At least eight percent of nominees were eliminated on Friday and Saturday in the primary elections of members and alternate members of the 17th CPC Central Committee and members of the Central Commission for Discipline Inspection.
The margins are bigger than those at the 16th CPC National Congress in 2002.
"Although the percentage of those eliminated is only some three points more than that in the 16th congress, it is a democratic step that would push forward socialist democracy with momentum and exemplary effect," said Professor Cai Changshui with the Party School of the CPC Central Committee.
The congress, which opened on Monday, has offered broader than ever information access.
Discussions of 34 delegations on the political report, delivered by Hu Jintao on behalf of the 16th CPC Central Committee, were open to more than 1,900 domestic and overseas journalists at designated periods of time.
Altogether 807 domestic journalists and 1,135 from 55 other countries and regions reported the congress, the most important political event in China in five years.
The previous congress, held in 2002, was covered by 850 overseas journalists and 570 domestic ones. The number of CPC members has been growing by 2.2 million annually in the past decade, and the total figure now stands at more than 73 million.
