BEIJING — China officially began its once-in-a-decade power transition today, with President Hu Jintao calling for vigilance against government corruption and saying the ruling Communist Party is at a critical juncture in its history.

Hu, who will move out of the country’s top political post in the coming months and is expected to be replaced by Vice Premier Xi Jinping next March, gave a state of the union-like address to more than 2,100 Party delegates at the opening of the 18th National Congress in Beijing. The congress will select a new ruling Politburo and pave the way for Hu to relinquish the reins.

Hu — the Chairman of the Communist Party of China — read an hour and 40 minutes of highlights from his 46-page work report, which addressed everything from pollution to employment issues, and was short on specifics and long on political buzzwords. Notably, he took up the issue of corruption, which has become a hot-button issue for the Party in this delicate transition year.

“We must thus make unremitting efforts to combat corruption, promote integrity and stay vigilant against degeneration,” Hu’s report read. “Leading officials at all levels, especially high-ranking officials, must readily observe the code of conduct on clean governance and report all important facts concerned.”

China’s top leadership has been under intense scrutiny this year, beginning with the arrest and conviction of the wife of former Chongqing Party Bo Xilai for murdering a British business associate. Bo was formally expelled from the Communist Party last weekend, along with former Railways Minister Liu Zhijun, who was accused in a major bribe scandal.

The Party’s reputation has suffered dramatically among the Chinese public over corruption, and it appears the leadership is well aware of the cost of the scandals.

Separate news accounts from Bloomberg and the New York Times have revealed that the families of both incoming president Xi Jinping and outgoing Premier Wen Jiabao have amassed vast personal fortunes as the men rose to power. At local government levels across China, officials have been accused of using their power for personal financial gains.

Said Hu: “We should ensure that strict procedures are followed in the exercise of power, and tighten oversight over the exercise of power by leading officials.”

Though he address the issue at some length, Hu did not name specific cases or legal measures to correct the problems. Theoretically, he did appear to state that the Party’s future legitimacy depends in large part on its ability to earn the trust of the Chinese people.

“The whole Party must bear in mind that only by taking root among the people and delivering benefits to them can the Party remain invincible,” he said.