Members of a visiting U.S. congressional delegation said here today they would oppose any move by the Reagan administration to certify human rights improvement in Argentina and resume suspended military cooperation while the current military government remained in power.

Rep. Michael D. Barnes (D-Md.), chairman of the House subcommittee on inter-American affairs and leader of the delegation, said the administration was considering moving within the coming months to meet the congressional requirement of a report certifying improvement on human rights here.

President Reagan must deliver such certifications to Congress for both Argentina and Chile before any military aid and sales to those countries, suspended during the 1970s, could be resumed. On Friday the administration made a similar certification to allow continued economic and military aid to El Salvador.

"This government should not be given a 'Good Housekeeping seal of approval'," Barnes said of the Argentine military administration in a meeting with American correspondents. Instead, he said, the Reagan administration should wait until a new civilian government takes over after elections scheduled for later this year.

Barnes and Rep. Barbara Mikulski (D-Md.), another member of the delegation, said human rights conditions in Argentina appeared to have significantly improved since the early years after the military takeover in 1976.

But, Mikulski said, "It seems unwise to certify a government that is at the lowest ebb with its own people. We should just wait to see if a constitutional government really occurs."

Reagan administration officials, hoping to resume arms sales and other military cooperation with both Argentina and Chile, placed a token sum of $50,000 in training aid for each country in the fiscal 1983 budget.

Formal certification to Congress, allowing the appropriation of the funds, has been long delayed, however. The delay has been caused by opposition both in Congress and within the administration, by Argentina's invasion of the Falkland Islands last year and by the priority of making similar certification for arms aid to countries of Central America, U.S. officials have said.

Some administration officials have also argued that the United States cannot resume military cooperation with one of the South American countries without including the other because of recent military tensions between Argentina and Chile.

According to Barnes and U.S. officials, a formula is now under consideration that would involve an administration certification of Argentina but not of Chile, where progress on human rights issues specified in congressional legislation is less clear. However, the certification of Argentina would not likely be followed by any substantial package of arms aid or sales and could be largely symbolic, officials have said.

Congress has little control over the president's human rights certifications, but would have authority over any subsequent arms agreements.

The congressmen, who visited Peru, Brazil and Chile before arriving here Thursday, said they found human rights restrictions in Chile significantly harsher than in Argentina.

"Chile should not even be under discussion for certification," Barnes said. "There is no way the president could, with a straight face, certify that Chile meets the requirements of the law."