Congressional leaders have agreed to a Carter administration plan to amend the strict new government code of ethics to head off a wave of threatened resignations by top officials.

Attorney General Griffin B. Bell said after a round of visits to Capitol Hill Monday and Tuesday that two sets of minor amendments will alleviate fears by officials-especially doctors and scientists-that rigid conflict of interest provisions might make them virtually unemployable after leaving the government.

Rep. George danielson (D-Calif.), chairman of the House Judiciary subcommittee that drafted the new code, said yesterday that he will introduce the amendments and hold a hearing on the proposed solution Monday.

Joseph A. California Jr., secretary of helath, education and welfare, said in a phone interview yesterday that the changes will "take care of the scientists and academicians I was complaining about."

A Defence Department official involved in the process agreed that the amendments will calm the concerns of Pentagon researchers, too.

The new law, which takes effect July 1, has become controversial because of its stringent financial disclosure provisions and limits on appearing before the government after leaving public service.

The most disputed provision of the new law has been one that bars a foremer government official for two years from "aiding and assisting" anyone appearing before the agency where he used to work.

The key set of amendments will make it clear that this prohibits only personal appearances in matters where the official was "personally and substantially" involved while in office, according to Bernard Wruble, who prepared the final amendments and the regulations, which will govern enforcement of the new law.

The other set of amendments would lower from 1,100 to about 140 the number of military officers who automatically come under the provisions of the act. This would make mandatory coverage only of three-star generals and admirals, a change thought more comparable to coverage of civilian officials.

Wruble said that, "95 percent of the problem was tackled" and solved in the administrative regulations, which will be made public Monday.

Amendments were needed to resolve part of the problem, officials said, because the controversial "aiding and assisting" provision carries a criminal penalty. "Regulations just can't address questions of prosecutorial discretion," a Bell aide said.

Danielson said the adjustments are needed be- cause "some of the phraseology in the act was not as artfully done as it ought to have been." He attributed the fuzzy language to the rush of the House-Senate conference committee at the end of the last Congress and the wide differences in the House and Senate Versions of the bill.

He said he heard no complains at the time from HEW and Pentagon officials who have since protested about the potential limits on future jobs outside government.

Some officials familiar with the evolution of the new ethics code blame the current problems on the administration's failure to anticipate how the bill would affect officials returning to the private sector.

"We got locked into a cockeyed position and are having trouble getting out," one Justice official said.

Bell said of the disputed "aiding and assisting" clause: "That was aimed at lawyers. But the shot missed and hit a lot of folks, doctors and scientists, nobody ever thought about."

Bell and Califano both noted the amendments will not help one category of officials, those returning to state or local government jobs. Wruble said the administration wants to see how the law works in the area before trying to make changes.

The proposed changes do not touch on the strict financial disclosure provisions, under which 15,000 top government employes will have to file detailed reports by May 15.

"We'll hear some hollering about that too as we get closer to May 15," one official predicted.