When Ferdinand Marcos and his wife Imelda stepped down from their separate "his" and "her" helicopters at the Washington Monument yesterday they were greeted by a band, flags, and several hundred cheering Filipinos and Filipino-Americans, some of whom wore T-shirts proclaiming "I Am a Filipino" and "One Country -- One Thought."

The turnout was the result of a concerted effort by the Philippine Embassy over the past few weeks to woo the local Filipino community and ensure that anti-Marcos opposition groups do not upset the Philippine leader's visit, leaving an impression with the American public that he is unpopular at home.

As part of this effort, the government has spent thousands of dollars on parties, picnics and receptions. Leaders of Philippine social and cultural groups have been telephoned by the embassy requesting them to urge their members to attend the functions. Some people received midnight calls with invitations to picnics the following day, according to one community activist.

Though their numerical strength in the U.S. appears to be small, the opposition groups are taken seriously by the Marcos government, which has laid charges of subversion in Philippine courts against several opposition leaders living here. In addition, opposition figures allege they have been the target of harassment and even assassinations by Marcos' agents.

One embassy worker privately expressed fears that the Marcos visit would be "rough" because of opposition activities that include plans for a prayer vigil at the White House, press conferences, picketing and even airplanes trailing anti-Marcos slogans across Washington's sky at rush-hour traffic time.

Opponents of the Marcos government have made their own attempts to drum up support in the local Philippine community. Yesterday, however, they were only able to attract about a dozen protesters, and they were kept well out of Marcos's eyesight by helicopters and a bank of low-branched trees.

How the 12,400 members of Washington's Philippine community, or the 770,000 Filipinos who live in the country feel about their government is difficult to tell.

Some, like Remo de la Pena, a retired computer specialist from Oxon Hill, approve of Marcos's strong-arm tactics as "necessary" and "mild" in comparison with other governments in the Pacific. Others are uneasy and disapproving of what they say is his disregard for human rights, his lack of tolerance for political dissent and what some call his attempt to set up a family "dynasty" in the island nation.

Several who were interviewed criticized the lavish spending for the state visit by a government that is deeply in debt and has much poverty among its 48 million people. "One thing that offends us is the grandiose preparations going on . . . spending so much for this . . . mainly it's for image-building . . . it's for international consumption," said a research assistant at the World Bank who did not want to be identified.

In the Washington area the Filipino community has a large percentage of professionals -- lawyers, doctors, economists. They are the fourth largest ethnic group among World Bank employes and many of them work in foreign embassies as receptionists, secretaries and drivers.

Filipinos have fit in well with American society, partly because of their familiarity with English. A measure of their economic success and adaptibility is the fact that two Filipino-Americans in Prince George's County this week ran for a seat on the central committee of the state Democratic Party. Acccording to the embassy the largest concentration of Filipinos in the metropolitan area is centered around Oxon Hill in Prince George's County.

The recent increase in the number of embassy-sponsored social functions involving local Filipinos reflect the new high profile the government wishes to show under the leadership of the new ambassador Eduardo Z. Romualdez, a brother of Imelda Marcos.

A large number of officials were sent in weeks ago to help the normal embassy staff do this work. Some, like Filipino actress Boots Roa, who is organizing cultural activities, will stay on as permanent embassy staff. Her husband, Peter, will be the manager of the first Filipino restaurant in the area. The restaurant will open in Georgetown next week -- an enterprise that has been facilitated by the embassy.

According to David Valderama, a Prince George's businessman who heads an umbrella organization called the Philippine Heritage Federation, some government officials helping to prepare for the visit said that "If they Americans don't see any demonstrations going on 'for' Marcos they'll think this guy is unpopular."

Opponents of Marcos charge that in addition to courting the local population, the embassy has been assiduous in countering opposition activity. One anti-Marcos activist said the posters he has been putting up around town each night were being scraped away by government supporters in predawn rides around town.