In a speech on the anniversary of its 1921 founding, Hu lauded the party for leading China's rebirth but made clear that pitfalls lie ahead as it continues to strike an ungainly balance between economic openness and political rigidity.
"The entire party must clearly see that, with the deep changes in the world, national and party situations, we face many new problems and challenges to improve the party's leadership and rule and to strengthen the ability to resist corruption and risks," Hu said.
Hu, who has been head of the party for nearly a decade, singled out corruption ? typically named in opinion polls as a top source of public discontent ? as a clear and present danger to the party's ruling legitimacy.
The fight against corruption is the key to "winning or losing public support and the life or death of the party," he said.
"Corruption will cost the party the support and trust of the people," the Chinese president warned.
Hu delivered the speech in a ceremony in the Great Hall of the People ? the Stalinist-style monolith at the heart of Beijing ? that was attended by thousands of party leaders and members and broadcast live on state television.
The party has sought to fan enthusiasm in the lead-up to the anniversary through an officially directed outpouring of nostalgia for China's Communist past.
The propaganda blitz has included a stream of laudatory media articles, the singing of "red" songs from Communist China's early years, museum exhibitions and the release of a film glorifying the birth of the party.
China also launched a key high-speed rail link linking Beijing and Shanghai, and opened the world's longest cross-sea bridge just ahead of the party fete.
But the campaign is widely viewed by political analysts as a facade to conceal the insecurities of a party that has jettisoned the ideology of its name and is struggling to deal with a range of complex problems without the flexibility that democracy affords.
These include an accelerating wealth gap, horrific environmental degradation, demands for autonomy from millions-strong ethnic minorities, and regular reports of corrupt and abusive officials.
"China's Communist Party at 90 is a bit like many 90-year-olds: increasingly infirm, fearful, experimenting with ways to prolong life, but overwhelmed by the complexities of managing it," China scholar David Shambaugh wrote in a commentary piece.
Hu conceded that "the whole party is confronted with growing pains," warning that many party officials were "incompetent" and "divorced from the people."
"It is more urgent than ever for the party to impose discipline on its members," he said.
The practice of securing lucrative party and government positions through connections and backroom deals is considered to be widespread.
Hu vowed a more merit-based personnel system and a drive to recruit talented young members into the 80-million-strong party, about 75 percent of whose card-holders are more than 35 years old.
"Young people represent the future of both China and its people. They also represent the future and hope of the party," Hu said.
The CCP was established in July 1921 in Shanghai as the brainchild of a dozen intellectuals, and took power in China in 1949 after defeating the rival Nationalists in a long and bloody civil war.
But the country was then plunged into nearly 30 years of chaos due to the misguided policies of revolutionary leader Mao Zedong that triggered political purges, famine, and social upheaval that left tens of millions died.
Hu made almost no reference to such events.
After Mao's death in 1976, Deng Xiaoping took over and launched a period of reforms that transformed China into the world's second-largest economy.
But the party's small group of elite leaders continues to exercise an iron grip on the country's political system, controlling the media and managing the world's largest military.
Analysts say China's lack of political reform has fuelled many of the problems now faced by the party and makes it difficult to root them out.
Copyright AFP (Agence France-Presse), 2011