"Since the reform and opening up, the fundamental reason for all the achievements and progress we have made has been our creation and development of the socialism with Chinese characteristics," Hu said in a speech during a ceremony at the Great Hall of the People.
The concept, frequently touted by the leadership, refers to the jettisoning of the centrally planned economy while maintaining strict authoritarian one-party communist rule.
The theory "not only showcases the vitality of contemporary Chinese Marxism, but also opens more room for further innovation of theories," Hu said during his 90-minute address, which was nationally televised.
"We need to draw on the beneficial fruits of mankind's political achievements, but we will never copy the model of the Western political system," Hu said.
The event at the Great Hall of the People - the seat of the country's legislature in the heart of the Chinese capital - was attended by more than 6,000 party leaders, legislators and military officials, who politely applauded throughout Hu's remarks.
The Great Hall was the site of a Communist Party gathering on Dec. 18, 1978, that endorsed small-scale private farming, the first step toward abandoning the late leader Mao Zedong's vision of communal agriculture and industry.
China's economy has since grown into the world's fourth-largest behind the U.S., Japan and Germany. Annual per capita income has soared to about 19,000 yuan ($2,760) last year, up from just 380 yuan in 1978.
Along with private enterprise and capital markets have come greater prosperity and stability than ever before.
Virtually all Chinese families now have at least one television and, in the cities, a washing machine — rare items three decades ago. Some 15 million families own private cars, and many Chinese also own their own homes.
"Nowadays, we worry instead about eating too well rather than not eating enough," says Guo Linchun, 78, retired music teacher in Beijing. "Now, living standards have improved so much, we see not only televisions, so many people even own cars."
The modern industries have also brought many modern ills: pollution, industrial accidents and product safety scandals. And China's heavy reliance on exports and foreign investment ensures that the uncertainties now afflicting the global economy are haunting the Chinese as well.
Hu said China needed to firmly focus on economic development to weather the current crisis.
"Standing still and regressing will lead only to a dead end," he said.
As economic growth slows and factories close, job losses threaten to fuel political unrest. Authorities have slashed interest rates and promised to spend more than half a trillion dollars to stimulate the economy.
The latest problems may widen a wealth gap that has already alarmed China's leaders, who worry about social instability caused by people who have missed out on China's economic boom.
"In the past 30 years, we attached great importance to promoting a harmonious society through achieving social equality while developing the economy," Hu said.
He also said one of the other great achievements of the last 30 years was "opposing Taiwan independence." China and Taiwan split amid civil war in 1949. Beijing continues to claim the self-governing island as part of its territory, and has threatened force if Taiwan declares formal independence.
And despite the massive growth and China's material wealth, it is still considered a developing country. According to the World Bank's most recent estimates, more than 100 million of the 1.3 billion Chinese still live on less than $1 a day. That's way down from 800 million three decades ago, but hundreds of millions more get by on just $1 to $2 a day.
Simmering protests over pollution and industrial accidents have prompted authorities to pledge better enforcement of environmental, labor and safety standards.
Associated Press writers Elaine Kurtenbach in Shanghai and Chi-Chi Zhang in Beijing contributed to this report.
Morey money-related links: