China has begun a week of festivities marking 50 years of Communist rule by hosting some of the world's wealthiest capitalists in the skyscrapers of a new Shanghai business district that evokes the space-age world of George Jetson. The Fortune Global Forum was designed, in the words of Zhou Mingwei, the dapper director of Shanghai's Foreign Affairs Office, as "a beacon of China's future."

A very different celebration has been planned for Friday in Beijing. There, in China's sprawling capital 600 miles to the north, a half-million people, closely screened for their "love of the motherland," will participate in a parade featuring goose-stepping students and soldiers accompanied by tanks, rockets and anti-aircraft weapons, a highly ideological tribute to the party's 50 years in power.

Marchers in Beijing will shout 50 slogans, all approved by the Central Committee of the Communist Party. An example: "Rely on the working class wholeheartedly." The parade, with dozens of floats decked out as oil derricks and pink apartment houses to symbolize modernization, will be closed to all but the hand-picked spectators. Half of Beijing will be under martial law for the event.

The contrasting observances in China's two main metropolises display with unusual clarity two seemingly contradictory strains of Chinese Communism today -- a desire for reform and openness with an insistance on a continued dictatorship and Marxist ideology. With their clashing pomp, the ceremonies also dramatize a fundamental problem faced by the Communist Party on the eve of the 21st century: Like many of the people they command, China's leaders face a crisis of values.

Two decades of economic reforms have freed millions of Chinese to create and pursue dreams the party itself never dared dream. But the party has had trouble keeping up, unsure of the philosophy it wants to implement at home and represent to the world.

China's Communist government pushed world revolution and rigid collectivism for 29 years after it was founded in 1949 with Mao Zedong at the helm. When Deng Xiaoping came to power in 1978, he switched the focus to economic development. Since then, the party has bounced around the ideological map in search of a value system to replace the doctrinaire Marxism that was left behind -- although never repudiated -- in the drive for economic progress.

The party leadership flirted with Westernization in the 1980s and won the backing of most Chinese. One party chief in those days even suggested that Chinese abandon chopsticks for knives and forks. But these ideas were shunted aside in 1989, when too many people wanted democracy too quickly and the party used army troops to crack down on student-led demonstrators in Beijing's Tiananmen Square.

After the crackdown, the party preached patriotism. Students were sent for basic military training, and patriotism was extolled in schools. Ultra-nationalism became a fad. But these ideas also ran out of steam. China could not completely reject the West; it needed its investment, markets and technology.

Traditional Chinese culture also became a party favorite. The party encouraged the people to resume martial arts training and study the teachings of ancient sages. Last year, the party embraced a campaign promoting "courtesy and Confucius."

But the return to China's roots has also proved dangerous. The popularity of spiritual groups such as Falun Gong was a product of party support for traditional culture. On April 25, 10,000 Falun Gong followers surrounded the Communist Party headquarters in Beijing, demanding their group be legalized. The party responded by banning movement and arresting more than 50 of its leaders.

"The government is in a bind in China," said Li Fan, an independent scholar in Beijing. "Marxism is finished. Westernization means democracy. But nationalism and traditional culture open other Pandora's boxes as well."

Most recently, the party launched a new campaign, ordering its 60 million members to resume the study of Marxism and atheism. Many party members acknowledge they belong to one of China's many religions; very few admit to being Marxists.

"Who do these guys think they are?" said one government official called on by the party to reconsider his attitude toward politics and morality. "I work hard for my government; I want them to leave me alone."

Faced with these issues on its 50th anniversary, the party is relying on two important sources of legitimacy -- foreigners in Shanghai and the army in Beijing.

Foreigners have played a key role in the party's quest to bolster its mandate. The presence of some 300 top foreign business executives at Fortune magazine's Global Forum in Shanghai's new convention center, and their intense jockeying for an audience with President Jiang Zemin and other Chinese officials, have already become fodder for China's state-run press.

But even while celebrating openness, Chinese authorities banned the current issue of Time magazine's Asian edition, which is devoted to China's 50 years under communist rule. The issue includes articles by the the Dalai Lama -- the exiled spiritual leader of Chinese-occupied Tibet -- and well known exiled Chinese political dissidents Fang Lizhi and Wei Jingsheng. Time is owned by Fortune's parent, Time Warner Inc., and was planning to distribute the issue at the conference.

Fortune's program also was apparently softened to appease the Chinese hosts, several sources said. A section on the complex problem of China's state-owned industries was scratched before the forum began. A session on the People's Liberation Army was canceled today.

The message in Beijing is more direct -- a manifestation of party power. The celebrations will mark the first military parade there since 1984 and the biggest military deployment in the capital since the Tiananmen Square crackdown 10 years ago last June. "The message is that no matter what, the party and the army are one," said a Communist Party member and scholar in Beijing. "They want people to see their power. It is that simple."

The capital has been swept clean of 100,000 undocumented workers from other provinces. Detention centers are full of them. Phalanxes of police patrol the streets. Factories have been shut down since Sept. 20 to clear Beijing's acrid air. More than $13 billion has been spent to spruce up the city, including construction of a new subway line, a new airport and wider roads.

The most unusual touch has been the appearance of dozens of electronic palm trees that decorate almost every major intersection like 20-foot-high sparklers. Tiananmen Square has been renovated with, among other things, two strips of turf imported from Oregon. Strings of lights adorn most major buildings along the city's main boulevard, Chang'an Street.

Long Xinmin, propaganda chief of the Beijing city government, said today that Friday's ceremony, commemorating Mao's Oct. 1, 1949, proclamation of the new Chinese state, will be "grand, warm and thrifty." The official price tag for the event is $36.6 million.

Some Chinese and Western scholars, pointing to the vaunted pragmatism of the Chinese, say the party does not need to believe in anything, that it can function as a patronage machine as long as it continues to deliver economic growth. But others say China's traditional view of itself as an exceptional nation -- the "Middle Kingdom" -- demands a new organizing idea to give the party a mandate to rule for another 50 years.

Gerald Segal, an analyst with the International Institute for Strategic Studies in London and author of the essay "Does China Matter?" in the September issue of Foreign Affairs, argues that China's unsure course is dangerous because it makes a return to the old way of thinking all the more possible.

"China faces a tough time whether it pursues real reform or not," he wrote, "but the lack of an organizing idea ensures that they are now lost in the sandstorm without a compass. . . . It is worrying that the default mode for the Chinese leaders is old style Communist propaganda. The Beijing parade is one example; so was the reaction to Falun Gong."

The lack of a clear belief system also has immediate consequences -- on privatization, for example. The party says officially opposes it, but since 1997, 16,000 small state-run companies have been bought or sold by individuals as local governments forged ahead with the process. Billions of dollars of state assets have been transferred into private hands in under three years.

As recently as this month, however, the party reiterated its support for state-owned enterprises. "At the eve of the 21st century, we are still endlessly debating whether to establish a market economy," wrote social critic Liu Junning in a widely read essay collection published last year. "Even the strongest proponents of a market economy have to hem and haw." Liu's book, "Political China," was subsequently banned.

Foreign policy is another area marked by the absence of open debate and a clear belief system. China often finds itself stating what it is against, but rarely what it is for. Since 1972, for example, when China joined the U.N. Security Council, it has abstained from voting 67 times -- more than any other nation by far.

Chinese foreign policy experts are beginning to chafe at the closed nature of the decision-making process. In an unusually pointed article earlier this month, Wang Jisi, head of the American Institute and China's Academy of Social Sciences, questioned why China is unable to take policy initiatives instead of reacting to other countries' proposals. The answer, he wrote, is that China has failed to define its interests. And the reason for that, many Chinese say, is that creativity is frowned upon, and the fear of making a mistake dominates the bureaucracy.

Officials complain that no one in China today can propose bold initiatives -- in the economy, politics or foreign affairs. The party leadership is split between two poles, just as the 50th anniversary celebrations are split between two cities and two faces of China. Li Peng, who carried out Deng's orders to smash the Tiananmen Square protests in Beijing 10 years ago, is No. 2 in the party hierarchy. Zhu Rongji, China's economic czar, who masterminded a much softer crackdown in Shanghai, is No. 3. Leaning first one way and then another is the party leader, President Jiang Zemin.

The festivities in both Shanghai and Beijing have been designed to heighten Jiang's stature. He went to Shanghai alone and will preside over the Beijing festival alone as well. He is the only living leader who will get his own float in Beijing's parade, third in line after Mao's and Deng's.