Hu made the comments in a keynote address at a ceremony in the Great Hall of the People -- the heart of political power in Beijing -- to party leaders and members gathered to celebrate the anniversary of the CCP´s founding in 1921.[break]
The event capped months of build-up tinged with revolutionary fervour of the past -- a nationwide propaganda blitz of laudatory media articles, red-song choruses, museum exhibitions and television shows.
"The whole party is confronted with growing pains," Hu said, telling the thousands-strong audience that "incompetence" on the part of some members and their "being divorced from the people" had created problems.
"It is more urgent than ever for the party to impose discipline on its members," said Hu, who has repeatedly warned that corruption could threaten the party´s legitimacy at the helm of the world´s second-largest economy.
"The Party´s development over the past 90 years has told us that firmly punishing and effectively preventing corruption is key to the winning or losing of people´s support and the life or death of the Party," he said.
"The fight against corruption remains serious and the task is still arduous," he added. "Corruption will cost the party the support and trust of the people."
Hu also hailed the achievements of the party "in revolution, development and reform" since it was founded 90 years ago by a tiny group of intellectuals, including a young Mao Zedong.
"Today a vibrant socialist China has emerged in the East and the 1.3 billion Chinese people are marching ahead, full of confidence under the great banner of socialism with Chinese characteristics," he said.
China, which likes to mark official anniversaries with pomp, has already released a star-studded patriotic film, launched a flagship high-speed rail link, and opened the world´s longest cross-sea bridge ahead of the party fete.
The nation´s first aircraft carrier could also go on sea trials on Friday, according to a Hong Kong Commercial Daily report that cited unnamed military sources -- a move that would garner worldwide attention on the anniversary.
The CCP was established in July 1921 in Shanghai as the brainchild of a dozen intellectuals. It took power in China in 1949 after defeating the rival Nationalists in a long and bloody civil war.
The country was then plunged into nearly 30 years of chaos due to policies enacted by revolutionary leader Mao Zedong that triggered political purges, famine and social upheavals in which millions died.
After Mao´s death in 1976, Deng Xiaoping took over and launched a period of reforms that transformed China into the economic powerhouse it is today.
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 a lack of social and political reform have fostered problems such as corruption, government abuses, illegal land seizures, a growing rich-poor divide and pollution -- issues that threaten the party´s future.
"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," David Shambaugh, a professor at George Washington University, said in a New York Times commentary.
But Chinese authorities are not letting these problems cloud anniversary celebrations -- newspapers are full of glowing editorials about the CCP, and upbeat slogans and huge flower arrangements dot cities.
An epic film recounting the Communist Party´s origins and featuring many of China´s biggest stars -- "Beginning of the Great Revival" -- is expected to smash box-office records.
And on the eve of the anniversary, Premier Wen Jiabao launched a new $33 billion high-speed train line between Beijing and Shanghai -- an event that was widely covered in the media.
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