Nearly three years after the fighting stopped in Vietnam, a new kind of battle is raging among Vietnamese refugees in this country - an ideological struggle for expatriates' hearts and minds.

"Long live the Socialist Republic of Vietnam," read a recent banner headline in one Vietnamese-language monthly printed and circulated in the United States.

"Residence keeps up attacks/Famine throughout the country," trumpeted a headline in a biweekly paper published here by Vietnamese refuges.

In September more than 100 Vietnamese traveled from Washington to New York to join a human rights demonstration countering a reception welcoming unified Vietnam's acceptance into the United Nations. Hours before the Vietnamese departed from Washington leaflets supporting the government in Hanoi had been strewn around their meeting place here.

In October dozens of Vietnamese refugees disrupted a showing of a pro-Hanoi movie on the Communist victory in South Vietnam at California State University at Fullerton. Nineteen Vietnamese were arrested.

All these were skirmishes in an ideological struggle that many Vietnamese in the United States expect to intensify with the presence of th Vietnamese U.N. delegation and the potential normalization of relations be the United States and Vietnam.

The main battlefield thus far has been the pages of Vietnamese-language newspapers. About a dozen refugee-published periodicals line up on one side with an explicitly anti-Communist stand. Usually printed in home basements and circulating no more than a few thousand copies each, the papers carry numerous stories on stringent control measures and harsh conditions in what was South Vietnam, based on accounts from recent escapees. The papers play up news items on resistance and revolts against the socialist regime, and economic deterioration in the country.

Standing alone on the other side is a 12-page tabloid called Thai Binh. Unlike the other papers, this monthly focuses on major official Vietnamese policies, new achievements and rosy aspects of the new life in Vietnam. It reprints articles from Nhan Dan, the official Hanoi daily.

"To Thai Binh, Vietnam is a sort of paradise; to the others [refugee-published papers], a hell," one Vietnamese journalist said with a grin.

Some secrecy surrounds Thai Binh. The paper prints neither its address and telephone number nor its editor's name, listing only a Post Office box in Santa Monica, Calif. Thai Binh is not available in Vietnamese grocery stores, a popular distribution channel for other Vietnamese papers. It is sent free to many Vietnamese in the United States.

Thai Binh calls itself "the voice of the Association of Vietnamese Patroits in the United States." The association also uses Post Office boxes.

Letters from a reporter requesting telephone interviews with both the editor of Thai Binh and the president of the association have been unsuccessful.

The president of the association, Nguyen Van Luy, met Vietnamese Premier Pham Van Dong at the Vietnamese embassy in paris during Dong's visit to France last spring and received a painting from him. Luy also led a Vietnamese group to greet Vice Premier and Foreign Minister Nguyen Duy Trinh on Trinh's arrival in New York to attend the U.N. session last September.

Born early last year after the "great victory of the nation," as Luy put it in a speech printed in Thai Binh, referring to the Communist conquest of South Vietnam, the association aims at "uniting widely all Vietnamese strata in the United States . . . in the spirit of reconciliation and orientation together toward the Fatherland . . . contributing to the consolidation and development of the friendship between Vietnamese and American people . . ."

Pursuing these purposes, the association has organized various gatherings including social parties, summer camps and movie showings.

Its chief supporters, according to informed Vietnamese sources, are some Vietnamese students who came to the United States years ago as recipients of American scholarships and who were involved in the antiwar movement here. The students "are young, bright, frustrated with the old regime and enthusiastic with patriotism. Without any experience with the Communists, they think they have embraced the right road to serve the country," said Nguyen Ngoc Bich, director general of information overseas under Nguyen Van Thieu's regime.

Thai Binh was named for a student killed in 1972 on his way home from the United States in an abortive hijacking of an Air Vietnam plan to Hanoi.

Pro-Hanoi activities appear to have negligible influence on most refugees. Thai Binh and Hanoi-produced films, however, attract some refugees who are curious to know what has happened in Vietnam. "I went to a movie showing once last year, hoping to see how life was going in Vietnam, but the film was heavy with propaganda and was very boring," said a young Vietnamese student at Northern Virginia Community-College.

In the Vietnamese refugee community - with about 150 associations, according to an official at the Refugee Task Force at the Department of Health, Education and Welfare - the anti-communist League for Human Rights Committee are the most active politically, particularly in Southern California and in the Washington area.

The committee organized two demonstrations in front of the White House this year in support of human rights in Vietnam and participated in another rally in New York last September. Under the sponsorship of the committee, some newly arrived refugees told those who had preceded them of the situation in Vietnam.

The chairman of the [WORD ILLEGIBLE] Ha Thuc Ky, formerly leader [WORD ILLEGIBLE] Revolutionary Dai Viet Party, which says was opposed to both communist and dictatorships in South Vietnam. A forestry engineer by training, the 58-year-old Ky said he had worked for a mapping firm in Maryland for 10 months until his grown-up American-educated children urged him to stay home "to have more time for (political) activities."

In Southern California, which has a large concentration of Vietnamese refugees, ideology activities are more animated. About half of the Vietnamese publications have headquarters in that area. Leading the Movement for Human Rights in Vietnam is Father Do Thanh Ha, a Roman Catholic priest who arrived in the United States 14 months ago after escaping the Communist ruled country. Father Ha, 41, of Costa Mesa, Calif., said his movement has the support from many prominent Vietnamese people in the area.

Nguyen Van Kim, one of the organizers of the league, said committees have been set up in some other states. "The committees share a joint position and coordinate activities, although we are not unified yet in a systematic organization," he said.