The White House is beginning a major "assessment" of the administration's political appointees that is expected to result in a personnel shakeup across the subcabinet level of the government in the coming months.

In part the assessment is an attempt by White House officials to regain some of the control over th machinery of government that they now believe should not have been surrendered to the Cabinet secretaries when the Carter administration ws first being formed.

No agency of government appears immune from the review, which will be aimed at weeding out political appointees who are considered in the White House to be disloyal to President Carter, incompetent or, in some cases, both.

However, likely early targets of such a shakeup include such domestic departments as Housing and Urban Development; Health, Education and Welfare; Commerce; Treasury; Energy, and Agriculture, which continue to be the subjects of complaints by presidential aides.

Most of the shakeup, whatever its scope, will probably take place after this fall's congressional elections as the administration prepares to enter the third year of Carter's presidency - the last year it will have before the onslaught of the 1980 presidential campaign. White House officials seem less bent on a wholesale purge of political appointees, replacing them with Carter loyalists, than in calculated moves designed to shake up the bureaucracy.

"We don't want people just sitting around out there," one official said in confirming White House intentions.

"We want to raise the adrenaline level."

Another aide suggested that the removal of a few of the "prime offenders" would "send a message" across the bureaucracy, resulting in the greater control and coordination the White House now seeks.

There is no evidence that the president plans changes among his Cabinet secretaries, upon whom he continues to heap lavish praise. "I am completely satisfied with every Cabinet member," Carter said two weeks ago in an interview with U.S. News and World Report.

But that sentiment is not shared by the president's top aides, who clearly would not be upset should a White House shakeup at the subcabinet level result in resignations of such top officials as HUD's Patricia Roberts Harris or Treasury's W. Michael Blumenthal.

The assessment - presidential aides shy away from words like "housecleaning" - is centered in a newly aggressive White House personnel office that has been placed under the supervision of Tim Kraft, assistant to the president for political affairs.

Kraft and his top aides are now the funnel through which Democratic Party officials throughtout the country make their wishes - and complaints - known to the White House. Thus, when an assistant secretary of a domestic agency fails to return the phone calls of a governor or mayor, it is likely to come to the attention of Kraft - who has control of the personnel machinery and the full backing of the president's chief political adviser, Hamilton Jordan.

The mere fact that White House officials are now speaking in terms of "monitoring what is going on in the agencies" and of "cracking the whip" represents a sharp break for the administration and a sure sign of the eclipse in White House devotion to the concept of "Cabinet government."

"They gave away the government," is now a frequent refrain of Whiate House officials, reflecting the views of even some of the aides like Jordan who participated in the giveaway.

That happened because Carter granted his Cabinet secretaries almost complete autonomy in filling the top jobs in their agencies. The predictable result was that many of the jobs went to people whose primary loyalty was to the Cabinet secretary and not the president and who often have been unresponsive to White House orders.

Presidential aides blame this development now on an "overreaction" to the heavy-handed tactics of the Nixon administration in trying to "run the government from the White House." They suggest that the Carter White House can gain more control over the administration without resorting to the same tactics.

"There are no illusions over here that a lot of the people out there are not Carter people and have their own agendas," one White House official said. "To the extend they can be accurately identified and replaced be real Carter people, it would be helpful."

But this official said an outright "purge" would backfire.

The White House is also extremely sensitive to Carter's public commitment to appoint as many blacks and women as possible and wary of the likely reaction to moves affecting such appointees.

"Obviously, it is not easy to make a move in that area," one official conceded. "It is much easier to move a white Anglo Saxon male than it is a member of a minority group or a woman."

There are other signs that the concept of "Cabinet government" is being chipped away at inside the White House. For example, Jordan recently instituted regular weekly meetings with representatives of government agencies at which White House complaints about lack of cooperation or outright "disloyalty" are a part of the regular agenda.

The Cabinet secretaries' autonomy in filling top jobs as they become vacant has also been sharply reduced.

"Now they have to check it out with us," oneWhite House official said.