FOR years, Yuan Biqing has scratched together a living in her one-room tenement, hunching over a worn slab of wood and pressing rice flour dough into Vietnamese dumplings. Like many of the 20,000 Vietnamese in China's remote province of Yunnan, Mrs. Yuan has been buffeted for more than a decade by the stormy relations between her country of birth and her adopted homeland. But recently her Vietnamese ethnic heritage has become less of a liability with Chinese neighbors.
Chinese residents of Kunming spurned Yuan and other Vietnamese as the warm wartime relations between China and Vietnam eroded after Hanoi's victory over South Vietnam in 1975. When China invaded Vietnam in a 17-day border campaign in 1979, the icy looks of Yuan's Chinese neighbors turned to outright hostility.
``Once when I lined up to buy vegetables, the Chinese clerk ignored me and insisted on selling to the Chinese lined up behind me,'' says Yuan, crouching on a wooden stool. ``When I asked why I was being passed over the clerk said: `Selling goods to Vietnamese is like feeding dogs.'''
``We faced all sorts of discrimination, but now things are much better,'' she says.
Both Vietnamese in Yunnan and provincial officials are welcoming the booming cross-border trade and eased tension resulting from Beijing's gradual rapprochement with Hanoi.
For Yuan and other Vietnamese who still speak to one another in their language of birth, better relations between the two states promise an opportunity to reunite with their families across the border.
Improved Sino-Vietnamese relations have also spurred hopes in Yunnan for the reopening of a vital commercial link from the poor, landlocked region through northern Vietnam to the sea.
``Such a development will be a great benefit to the province's economy and its efforts to open to the outside world,'' Chu Chenhua, director of trade and foreign affairs at Yunnan's Economic Planning Commission. ``But it all depends on a settlement of the Cambodia issue.''
Beijing says it will not fully normalize ties until Hanoi completely withdraws from Cambodia and helps coax the warring Cambodian factions into electing a popular government under United Nations supervision.
ALTHOUGH Beijing still keeps Hanoi at arms length, thousands of Chinese on the border seeking to barter goods and revive family contacts have embraced their southern neighbors. In 1986, border residents from both countries began trading goods at five ``grass streets,'' or clearings in wooded areas along the frontier.
This year such trade has more than tripled to at least $6 million at 16 ``mutual fair trading points'' on the border. The figure is 10 times higher than official trade prior to the Sino-Vietnam conflict, when Vietnam was too embattled and dependent on China's aid to be a significant commercial partner, Chu says.
The two border economies are complementary, with China offering consumer goods like sewing machines, fans, and radios and Vietnam providing rice, timber, and oxen, he says.
Yunnan is hoping for a fillip to trade from the restoration of the Kunming-to-Haiphong railway, Yunnan officials say. The narrow, 3.3-foot-gauge line would cut 600 miles off the distance Yunnan goods must travel to the sea on the railroads across southern China, Chu says. He declined to confirm reports that the two countries have discussed restoring the line, which carried Chinese and Soviet arms to Hanoi during the Vietnam War.
Despite the better prospects for Yuan and her home province, longstanding hostility runs just below the surface of renewed Sino-Vietnamese fraternity.
China's leadership has sought to play down enmity with their communist counterparts in Hanoi.
Although readily adopting many aspects of China's civilization, Vietnamese have often bristled at China's attempts at political domination.
Yuan consented to a benign sort of Chinese hegemony. Her late husband, a soldier in China's Nationalist Army sent to secure northern Vietnam from Japanese forces after World War II, took her back to Kunming in 1946.
After four decades in one of China's most impoverished provinces, Yuan is too poor to travel to see her family in Hanoi.
``Now the door is opening again, but I don't have enough money to go through it,'' she says, smiling broadly beneath a photo of Ho Chi Minh.