President Carter's proposed $50-per-person tax rebate came under continued fire from skeptics in Congress yesterday.

Sen. Ernest F. Hollings (D-S.C.) wondered whether a tax cut was what Carter had in mind when he called on the country to make "sacrifices" during his fireside chat Wednesday night.

"While he's asking for sacrifice, his team is up here asking us to give everybody 50 bucks," Hollings said at a Senate Budget Committee hearing on the President's proposals to stimulate the economy.

Other committee members also mocked the rebate idea, but Treasury Secretary W. Michael Blumenthal and other administration policymakers said a rebate is the only way to give the economy the quick fix it needs."

"No one likes it," Sen. Lawton M. Chiles Jr. (D-Fla.) summed up, "but the problem is, is there another way to quickly put more money into the economy."

On the House side, meanwhile, more and more members of the Ways amd Means Committee, which has begun hearings on the Carter plan, seem inclined to limit the rebate if they do approve it.

They want to phase it down or out for taxpayers with incomes in the higher brackets - those making $20,000 to $30,000 and up.

The committee heard yesterday from a panel of seven business and labor spokesman and independent economists who agreed on almost nothing.

Thus economist Walter W. Heller, who was chairman of the President's Council of Economic Advisers in the Kennedy-Johnson years, said the Carter plan - $31.2 billion of pump-priming over two years - is "unduly modest in size," while Hendrik S. Houthakker, CEA member in the first Nixon administration, said "our economy is growing steadily and does not need emergency measures" of any kind.

Reginald H. Jones, board chairman of General Electric Co., called for a permanent tax cut for individuals rather than a rebate, plus an increase in the tax credit for corporate investment.

But AFL-CIO economist Rudolph Oswald said that "there is no economic justification for giving business a new tax windfall," and that there ought to be no tax rebates or cuts at all - that stimulus should come from increased federal spending on public works, housing and public-sector jobs.