The Chinese textile worker and her Arab student boyfriend had continued their love affair for more than two years before they became a diplomatic casualty.

He was recently graduated from China's most prestigious university after years of study and hoped to take her back home to South Yemen as his bride this month.

But a simple love story ended in tragedy after they failed to get permission from their two governments, which are adversaries in China's quarrel with the Soviet Union. g

On Monday night, the young lovers sat down at a plain wooden table in his spare dormitory room and each swallowed a small bottle of a poisonous insecticide.

While they lay dying in different hospitals, other students returned to the room. There they found a color photograph of the couple holding hands and two suicide notes blaming their governments for driving them to such an act.

With its Shakespearean flourishes, the double-suicide overstates the general problem of forming personal relationships in China among foreigners and local residents. Even as an extreme example, however, the sad incident dramatizes a special kind of social pressure in a nation that only recently opened its doors to large numbers of foreigners.

This pressure creates a dilemma for Peking, which hopes to attract foreigners to help study its problems and modernize its economy while keeping the foreigners from infecting Chinese citizens with rising expectations of a better life.

Unlike the suicide case, Peking alone normally stifles such contacts with a confusing set of rules and pronouncements that make it unwise and often dangerous for Chinese to cultivate friendships with foreigners.

Few Chinese have regular contact with foreign students, businessmen or journalists without being questioned by security police or warned by the units that oversee their work and social life. Entering hotels for foreigners in Peking is impossible for most Chinese without registering their names and units. Receiving gifts from foreigners is strictly prohibited.

Chinese who have regular dealings with foreigners as part of their job are supposed to follow regulations forbidding such actions as revealing family background. An American businessman in Peking recently discovered that the mother of a Chinese colleague was a famous writer, but the colleague refused to acknowledge the discovery until he got permission from his unit leader.

Even more restrictive are Chinese views of romantic interludes with foreigners, a position that transcends normal political xenophobia into cultural and racial bias, especially against dark-skinned Africans and Arabs. c

At various colleges with swelling enrollments of foreign students, authorities try to discourage mixing with foreigners. Some foreign students complain that Chinese friends get harassed -- and even disappear -- if suspected of intimate contacts with them. Chinese women who date foreigners are generally regarded as prostitutes.

Although Westerners in China occasionally manage to overcome the cultural stigma and even marry Chinese in some cases, discrimination continues to plague the large number of Africans and Arabs sent to China by their governments for long, lonely years of study.

The despair that can arise from such bias threaded the suicide letters left Monday night by Nassar Adam, the student from South Yemen, and his girlfriend from Tianjin, whom acquaintances remembered only by her surname Cong.

Although the letters were seized by Chinese police, several students read them first and memorized their contends as a reminder, they said, of the human misery that can result from government intrusion.

Cong's surviving words reflected the hopelessness of a woman who called herself "just a common worker with no power."

"Because I love a foreign man, can one say I am no good, that I am selling out my country or selling myself?" she wrote, according to friends who read the letter.

She apparently had asked her work unit for permission to marry, said a friend, but the leaders turned her down. So, she is said to have written, "I do not have the power to marry the man I love. Committing suicide is the last solution."

The suicide message of Adam, written in Arabic, was tinged with the desperation of a man caught in bureaucratic switches. He had asked the South Yemeni Embassy in Peking to appove his marriage plans, but was still awaiting a reply just days before he was scheduled to leave China.

"I am about to leave and they [the embassy] know that well," he is said to have written. "I wish I weren't living anymore."

Why the South Yemen Embassy failed to respond to the request remains unclear. One seasoned diplomatic observer suggested that the small African state may simply have tried to avoid further straining of its relations with China by deferring to Peking's dislike for such marriages.

South Yemen, a Marxist state located in the southern tip of the Arabian Peninsula, is closely aligned to China's chief adversary, the Soviet Union. Embassy officials refused to discuss details of the suicide case.