Rep. Dan Rostenkowski (D-Ill.), the chairman-to-be of the key House Ways and Means Committee, said yesterday he expects "extensive" and "healthy" discussions in the House of any spending cuts proposed by the new, Republican administration.

In an interview, Rostenkowski emphasized that he and his Democrat-controlled committee would "in no way play an obstructive role," but he indicated it would be difficult to cut the budget significantly.

"I am not about to see programs which have been successful be dissected," Rostenkowski said, citing the Social Security program as an example.

The Chicago Democrat refused to go into detail on his views of tax and spending policy for next year, saying that he intended to wait until President-elect Ronald Reagan makes specific recommendations.

However, Rostenkowski pointed out that President Carter also had come to Washington hoping to cut spending and balance the budget. The prospective Ways and Means chairman said he did not want his comments to be interpreted in any way as being uncooperative, and he said that he would not discourage a proposal to initiate swift spending and tax-cut measures if "the solutions to our problems are not too drastic."

"What we're really talking about, although no one wants to admit it, is sacrifice. And I want to know whether that same majority of the American people who voted for a new president and Senate are really going to want sacrifice," he asserted.

The new administration will have to look at things such as price supports for farmers and the automatic increases in Social Security payments in line with inflation, Rostenkowski said, as "these are things that with the limited amount of tax money collected are not sustainable." He added, "I hope they bring a magic wand."

The congressmen fully supported an early tax cut next year to stimulate the economy and "work climate." He said Reagan "has a full wind in the sails of tax reduction" and should use it, "and we should too." Although House Democrats opposed enactment of a tax cut before the election, there was "always a unified feeling that a tax cut is necessary," he said.

Asked whether his committee would oppose the controversial Kemp-Roth plan for a 10 percent cut in tax rates for three successive years, Rostenkowski replied that he did not want to say "no Kemp-Roth." But he indicated that he thought Reagan may not push this measure. "I wasn't aware of any great eagerness on the part of Republicans on the committee to push Kemp-Roth," he said.

There will be a "sweet aroma" of cooperation to get a tax bill to the floor of the House, he said, at least until after testimony is taken from economists, the panel has discussed whatever proposals are made and he has tried to get a consensus from the Democrats on Ways and Means.

On a proposal from the director-designate of the Office of Management and Budget, David Stockman, that Reagan should declare a national emergency on taking office, Rostenkowski said, "Sure, they should take advantage of their momentum. . .

There is a glistening aura of the presidency for the first six months or so."

But he warned that governors and outsiders coming to Washington often overestimate the awesomeness of the presidency and think that they can rush Congress into action much faster than is possible. On the spending side "there will be extensive discussions, I'm sure," he said.

Stockman has warned that, unless the new administration quickly pushes for a program of significant spending and tax cuts, it could be engulfed in economic problems brought on by high interest rates and inflation.