Xi urged officials at all levels to obey anti-corruption regulations and to better limit their relatives or associates from abusing their influence for personal gain, but he gave no indication of any independent mechanism for investigating graft.
The party, which controls courts, police and prosecutors, has proved feeble in policing itself yet does not want to undermine its control by empowering an independent body. Some officials have been required to report income, real estate holdings and other wealth to their superiors since 2010, but the measure has done little to staunch graft.
Xi took over as China's top leader last Thursday when he assumed the posts of party leader and head of the military commission from President Hu Jintao. Hu will retain the title of president — the ceremonial head of state — until next spring, when he hands that position to Xi as well.
Xi has been gradually replacing key Hu-appointed party officials.
On Monday, former public security minister Meng Jianzhu was named head of the Political Science and Law Commission that oversees police and the courts, replacing Zhou Yongkang.
Zhao Leji, the former party boss of the northern province of Shaanxi, was named the new head of the Organization Department responsible for key government and party appointments. He takes over from Li Yuanchao, a Hu ally who last week failed to gain a seat on the all-powerful Politburo Standing Committee.
In his remarks to the Politburo, Xi dwelled on the importance of the party's theoretical foundations in Marxism, Leninism and the ideas espoused by his predecessors, but his remarks on corruption stood out for being relatively free of political jargon.
Xi also emphasized the need to narrow the gap between the party and the people in what seemed like an implicit critique of his predecessors, said Willy Lam, a political analyst at the Chinese University of Hong Kong.
Lam said Xi's frequent references to "the people" in his speech indicated that "the past two decades have resulted somehow in the people feeling alienated from the party."
"Now what he's saying is that from day one is that we shall stick to the people. We will do what the people want," Lam said.