On the dusty, sandy roads in China's westernmost city, the language that is heard most often above the jingle of the bells on the donkeys is not Chinese but Uighur, a mixture of Turkish and Persian. Five times a day, the call of the muezzin pierces the air and the donkey carts are tethered as their drivers, heeding the call to the faithful, head for nearby mosques.

Here in China's strategic northwestern province of Xinjiang, 60 miles from the Soviet border, the presence of the Uighurs (pronounced way-gurs), a Turkic people of Moslem faith, is clearly felt. In fact, the Uighurs, who make up 80 percent of this city's 180,000 population have more in common with their brethren on the other side of the border than with their comrades in Peking, 3,500 miles to the east.

Xinjiang, China's largest province, is home to 40 of China's 55 minority groups that together make up only 6.7 percent of the country's population. In Xinjiang, the Uighurs are the dominant majority, composing almost half of the region's 13 million people.

Relations between the minorities and the Han Chinese, who make up the vast majority of the country's population, have historically been uneasy here. The Han Chinese are named for the Han dynasty that laid the foundation for the Chinese empire more than 2,000 years ago.

For decades the Peking government has been sending Han Chinese to outlying regions like this one to develop the areas economically and assimilate the minorities into Chinese culture. In recent years, however, the government has moved to ease tensions between the Han Chinese and other ethnic groups by guaranteeing the rights of members of minority groups. Today the minorities have equal rights under the law and within the Communist Party.

But despite these efforts, by August 1981 relations between Chinese and Uighurs in Xinjiang had deteriorated so badly that China's most powerful leader, Deng Xiaoping, traveled from Peking to Xinjiang to help mediate the political infighting between Chinese and Uighur members of the provincial ruling committee, diplomats said then.

According to the September 1981 issue of the Hong Kong Communist magazine Cheng Ming, Deng discovered an "unsteady situation." The magazine said Uighur dissidents had planned a province-wide uprising against Chinese rule, using the slogan, "We want self-rule and don't want to be dominated." Peking's response to the communal fighting and ethnic group demands was to replace the Communist Party leader with Gen. Wang Enmao in November 1981.

Wang had helped bring the region under Communist control after the party came to power in 1949, and his moderate and pragmatic policies reportedly have earned him support among the people.

Now, as Xinjiang prepares to tackle an ambitious modernization plan to transform China's wild west into China's California by the end of the 21st century, much of its success will hinge on its leaders' ability to achieve ethnic unity and political stability.

The easing of tensions on the Sino-Soviet border in recent years and the reopening of two border posts in Xinjiang for the resumption of trade between the two countries has also allowed the region's leaders to devote more energy and time to internal stability.

In a recent interview, Wang, the province's top political and military leader, described relations between the Han Chinese and the minorities as "very good," a marked improvement from 1982, when he noted that there were still "serious problems."

Although local residents say there has been no more of the violence that pitted Uighurs against Chinese in 1980 and 1981 in at least two Xinjiang cities, there is a feeling of wariness. "Small frictions," caused by misunderstanding over customs and traditions and the inability to communicate, are common, local residents say.

On a recent Sunday, a group of about 20 Han Chinese youths crowded in front of one store, some smoking cigarettes, all listening to western pop music blaring from a large cassette recorder. Not a single non-Chinese went near them. Instead, they steered clear of the group, some even crossing to the other side of the street to do their shopping.

The misunderstanding and prejudices are particularly common among the younger generations of Han Chinese and Uighurs. There have been instances, for example, when young Han Chinese intentionally have stood in front of praying Uighurs to offend them.

"The Chinese youths who do this look down upon the Uighurs. They do this because they like to pretend that the Uighurs are kowtowing to them," one source said.

When Uighurs are in a funeral procession, it is considered a sign of respect for approaching cyclists to dismount, but many of the younger Han Chinese either do not know better or choose not to, the source said.

Accentuating tensions are the frustrations felt by many of the Han Chinese, many of them skilled workers and technicians sent from China's larger coastal cities, such as Shanghai, to help provide the needed personnel for Xinjiang's economy. They have a hard time adapting to the harsher conditions of life here, Chinese sources said. In addition, they often become frustrated professionally because they are cut off from the latest information in their specialty.

In 1980 and 1981, there were clashes caused by unrest among the former residents of Shanghai who had been sent to the region in the 1950s and who were demanding to return to their native homes. When authorities refused, about 10,000 demonstrated in Aksu, 250 miles northeast of Kashgar. Government offices were taken over and officials attacked before order was restored. Although all of China's different national minorities are equal under the law, they usually have a much lower standard of living than the Han Chinese.

"Yes, in reality there are still disparities between the Han and the minorities because they are not equal economically," said secretary Wang. "And where there are disparities in income , there will be friction."

China has had a history of quelling the central Asian minorities to assert control over its western frontier. Despite the high-minded policy on minorities, Communist leaders have long encouraged and sometimes forced migrations of Han Chinese settlers to the so-called autonomous regions -- set up to allow the ethnic groups some degree of freedom and a chance to maintain their traditions -- to dilute the ethnic influcences and ensure central control over China's troubled borders.

This was especially true in Xinjiang, where the Uighurs and other Moslem minorities have long-standing ties with the Turkic people in the Soviet Union. Part of the province was ruled by a Soviet-sponsored semiautonomous regime before the Communist takeover of China in 1949.

Since 1949, more than 5 million Chinese have been brought to Xinjiang from eastern China to help assimilate the Uighurs, Kazakhs, Kirghiz and Mongols. These ethnic groups are considered to be among the most rebellious minorities in China.

The integration effort began in 1958, with the founding of rural communes, curtailment of private plots and attacks on religion, specifically Islam. Discontent among the minorities was reflected in the exodus of more than 60,000 Kazakhs across the border to Soviet Kazakhstan in 1962.

The assimilation effort reached its peak during the Cultural Revolution from 1966 to 1976 when the Arabic alphabet was outlawed in favor of the Latin alphabet, mosques were closed and turned into workshops, Moslem classics were burned, restrictions were imposed on the number of sheep minority peasants could raise, and Han officials delivered speeches in Chinese without providing interpreters.

In 1981, ethnic tension flared in Kashgar when a young Uighur peasant who was digging a ditch got into a fight with a Han Chinese. Neither was able to speak the other's language. In a fistfight the Han was beaten by the stronger and bigger Uighur. Angered, the Han went into his store, took out his hunting gun and shot the Uighur.

While the police searched for relatives of the dead peasant, an angry mob took the body and paraded it through the streets. The mob killed two Hans and beat many others, according to a report last year in the Communist Party newspaper People's Daily.

Wang said the dead Uighur's father, who was supported by his son, received compensation from the government. The dead Uighur's sister, who was also supported by her brother, was given a job in a school in the city, he said. The funeral costs were paid by the state. The Han and an accomplice were executed, according to Hong Kong newspapers.

Since 1978, Peking has tried to ensure ethnic rights and religious freedom and elevate minority group members to leadership positions. Now the head of each of the region's 80 counties is a member of an ethnic minority, said Bahar Rahim, an official working on minority affairs. The Arabic alphabet is back in use and there is no longer a limit to the number of sheep a peasant can raise.

In addition, the government has begun allowing people to make the pilgrimage to Mecca required of devout Moslems, and relatives from the other side of the border have been allowed to visit Xinjiang. Those who have relatives in the Soviet Union also have been allowed to visit there, officials said.

Emphasis has been given to education, with quotas of up to 60 percent set aside for minorities entering the region's colleges. Since 1982, the regional government also has given rewards to those who have contributed to ethnic unity during an "ethnic unity month" each year.

Some of the minorities who now hold party and leadership posts are among those who most insistently deny that any tensions exist.

When told that some minority leaders in the United States resent what they call tokenism, Abdul Ahet Mohammedjan, Kashgar's deputy mayor for trade and finance, replied angrily: "I have power, I have a post and I have responsibility. This is not like the United States."

But here in Kashgar, despite all the talk about ethnic unity, there is no formal program for the Han Chinese to learn minority languages, although there are many programs to teach the Uighurs to speak Chinese.

Pragmatists like Wang acknowledge that there are many problems. As Xinjiang tries to increase its industrial and agricultural output five-fold over 1980 by the end of this century, it will have to rely heavily on skilled workers and technicians from the interior.

To lure them here, Wang said, the region this year began giving material incentives. Those with a college education will automatically receive a one-step increase in wages when they first arrive. Every three years after that, another increase is guaranteed. The wage incentives are significant because they are a marked departure from the past, when the Han settlers were told that the glorious task of building up the border area was enough compensation for their work.

Cedi Wakaz, 67, a Uighur, said he does not have many complaints. A retired shepherd, he spends most of his free time taking care of the mosque across from the Abakh Hoja mausoleum, the holiest of pilgrim resorts in southwestern Xinjiang.

On a recent Sunday afternoon, his chores completed, he was relaxing in the sun on a straw mat.

"I was born here. I have a wife and two children and two grandchildren," he said. "We all live together. Life is not bad. I have five mou [five-sixths of an acre] of land, four sheep and six chickens. I have enough for myself."