Harvard libraries may have to make significant service cutbacks if President Reagan's 1985 budget passes unamended through Congress.

The Reagan budget would eliminate all federal grants to research libraries--a drop from last year's outlay of $5 million.

Last year, however, Reagan also attempted to phase out all aid to research libraries, but Congress amended the proposal.

Harvard currently receives approximately $250,000 annually in federal library grants.

The loss in aid would mean "drastic" cutbacks in services such as microfilming and book preservation, said Sally Williams, budget and planning officer for the Harvard libraries.

Library officials also said that the cuts may mean a reduction in staff size.

The decrease in aid would have "grave implications" for the material scholars use for study, said Kenneth Carpenter, librarian for research and publication.

"We would have to severely decrease what we have available in our preservation collection. Without the aid, the books are likely to rot away before we will be able to preserve them," he explained.

Federal funding has allowed Harvard libraries to microfilm more than 10 million pages, but this accounts for only a small percentage of what needs to be filmed, according to Carpenter.

Over the past few years the cost of supporting research libraries has increased significantly, but federal grants and private gifts have managed to "keep libraries from decaying," said Parker L. Coddington, director of governmental relations.

He added that the value of the libraries current collection would be "severely diminished" with no funding.

But Congressmen, Washington lobbyists and Harvard administrators predict that Congress, as in past years, will amend the proposal.

"We can expect strong support in the Congress, and it is likely that there will be no significant cuts," Coddington said.

In other budget matters, Reagan proposed cutting $600 million in financial aid from higher education and increasing science research grants.

Harvard administrators criticized the financial aid cuts saying that the move would greatly reduce programs including supplemental grants, national direct loans, and student incentive grants Guaranteed student loans, however, would receive increased governmental support.

Harvard could lose about $1 million in supplemental grants alone, administrators said.

But Harvard could gain about $4 million in federal research grants which proposes an overall 10 percent increase over last year's budget for basic research grants, which would bring the total amount of research aid to $7.9 billion for 1985.

The grant includes a $211 million rise in National Science Foundation aid--which support most Harvard research projects--and a $207 million in increase in National Institute of Health funding, "which is of primary importance to the Medical School." Coddington said.

Most officials agree that Congress will support the increases and amend the reductions.