“The Chinese people and nation have a great and bright future ahead,” Mr Xi told party delegates as the meeting came to a close.
“At this great time, we feel more self-confident and proud. At the same time, we also deeply feel a heavy sense of responsibility,” he said.
The concept Mr Xi has touted is seen as marking a break from the stage of economic reform ushered in by Deng Xiaoping in the late 1970s and continued under his successors Jiang Zemin and Hu Jintao.
In a sign of Mr Xi's greater clout, his name was attached to his theory, putting him on par with Mr Deng and communist China's founder, Mao Zedong.
The placement of Mr Xi's thought among the party's leading guidelines also comes five years into his term - earlier than his predecessors.
Mr Xi has described his concept as central to setting China on the path of securing a “decisive victory in building a moderately prosperous society in all respects”. He's set the target dates of 2021 - the 100th anniversary of the party's founding - and the People's Republic's centenary in 2049 - for the establishment of a prosperous, modern society.
While China has the world's second-largest economy and legions of newly wealthy urban residents, it continues to rank 79th in the world in terms of per capita GDP, according to the International Monetary Fund.
The move came at the close of the 89 million-member party's twice-a-decade national congress at Beijing's hulking Great Hall of the People, where nearly 2,300 delegates gathered to elect the party's leading bodies and hear reports.
Although the delegates nominally have the power to vote on candidates, all choices are carefully vetted and the outcomes decided by negotiations among the top leaders.
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