Mao Tse-tung's successors have slowly dismantled China's once-ambitious program to provide revolutionary leadership and technical aid to the Third World, and are concentrating their energies and rhetoric instead on improving the standard of living at home.

A decade ago, Chinese engineers and workers were busily completing a railway that Western analysts feared would not only link Tanzania and Zambia but also extend communist influence and subversion deep into southern Africa. At the same time, China was pouring large amounts of help and money into Vietnam's ultimately successful war against American forces.

Today, in Deng Xiaoping's China, it is difficult to find anyone who will defend, much less praise, either of those efforts. Help to Vietnam "was Chairman Mao's most serious error," a student at Beida University told a recent visitor, adding later in the conversation that "China is too poor to help all those African countries, too."

China's Great Turn Inward is now a matter of deliberate policy rather than an unintended result of inattention to the rest of the world, as it was during the years of the Cultural Revolution and the final, disputed phase of Mao's rule that followed. Moveover, it reflects a crucial turn for the Third World in times that are hard not only on national balances of payments but also on international revolutionary ideals.

In China, Egypt and other Third World nations that came to independence under political demigods who are now dead, successor governments' are whittling down the unwieldy legacies of the departed giants by directly or indirectly blaming their grand international designs for bringing economic damage and lower standards of living for their own people.

As Anwar Sadat did in Egypt after Gamal Abdel Nasser, Deng has relentlessly promoted a China-first policy in which materialism in the here and now replace Mao's commitment to a common front of anticolonial nations in Asia, Africa and Latin America, the "countryside" that would eventually overwhelm the "city" formed by the developed nations.

Furthermore, like Sadat, Deng has been able to capitalize on the fading memory of colonial times and the end of American involvement in Vietnam to argue that economic cooperation with the West helps China confront an expansionist threat from the Soviet Union.

"In recent years, China's economy has not been in very good shape and we have been readjusting our economic programs," Vice Foreign Minister Zhang Wenjin said in an interview. "The period of large-scale economic aid to African countries is over. With the development of China's national economy, it may be possible to provide more economic aid in the future.

"China belongs to the Third World," he continued. "Our conditions are about the same as other Third World countries. There should not be any talk about leadership of the Third World."

Like the captain of a giant ocean liner, Deng has been slowly turning his nation degree by degree toward his program of economic "readjustment" and away from what he and his followers describe as the radical and disastrous programs of Mao's widow, Jiang Qing, who is now being blamed for every aspect of the visible failure of the Chinese economy in recent years in terms that skirt close to Mao himself.

"Those housing units were built shortly after the fall of Jiang Qing and her accomplices," a government translator said as he and a visitor passed a new apartment development. "Even though the shortage had become very serious and the people were angry, the Gang of Four stopped the Central Committee from doing anything."

An arrival at Peking's new and, for the moment, empty air terminal, where a string of Boeing intercontinental jets with China's red flag painted on their tail assemblies sit silent on the runway waiting for future tourist multitudes, is disorienting for a correspondent whose first encounter with the Communist Chinese came in Tanzania a decade ago during the building of the Tanzam railway.

In that era, when American officials briefed reporters on the sinsiter designs of the Chinese in Africa, the Chinese engineers and workers responded to all overtures for discussion with sullen silence.

Today, an arriving American in China is likely to be greeted with friendly smiles and a willingness to discuss China's problems -- a startling change from China's own attitudes two or three years ago and from most Third World countries today.

"Three years ago when I arrived you had to pretend that you had just arrived in Paradise," a Western diplomat said. "When a visitor asked sympathetically how China dealt with handicapped persons, we were told that China had no handicapped persons. Now, the leaders acknowledge in speeches to the nation that there are 100 million hungry people in China and 20 million unemployed, and ask for help in overcoming such problems."

At the Two Bridges Commune on the outskirts of Peking, the welcoming banner does not contain one of Mao's revolutionary slogans.Instead it exhorts the 43,000 residents, who are divided into six production brigades, to "March Forward to the Four Modernizations."

Commune leader Yu Xi Ho gives visitors a detailed description of the "management and marketing" problems of the collective farm and workshops he controls, saying that under the "four modernizations" his unit expects to be able to buy farm machinery from the United States and to begin to send some of its members to Japan to study more efficient agricultural techniques.

China's long-term economic planning calls for modernization in four areas -- agriculture, industry, defense and science-technology -- to take priority. For Yu Xi Ho, the modernization program's most important and immediate result should be a rise in the standard of living for China's peasants and workers.

"During the Cultural Revolution we were lagging behind in terms of technology. It's time for us to catch up. We are a poor country. We want to help other countries, but we will be limited in what we can do until we catch up from the damage of the Cultural Revolution," he said.

A small group of students at Beida University were vociferous in condemning what they saw as the grandiouse efforts for international solidarity undertaken by Mao. Their questions to a visitor concentrated on methods for getting scholarships to study in the United States rather than on world politics.

"Chairman Mao was wrong to give all that aid to Africa and especially to Vietnam," said one student in response to questions. "The Vietnamese have just used it to build themselves up to attack us. And our peasants are just as poor as Africa's peasants. We must help ourselves first."