The government here will meet the price Rep. Clarence D. Long (D-Md.) put on his crucial House committee's approval of $60 million in U.S. military aid by releasing political prisoners and allowing unannounced inspections of penitentiaries and police cells, Long told a news conference today.

The chairman of the subcommittee on foreign operations of the House Appropriations Committee said he also had "encouragement" that the Reagan administration will meet not only his demand for a special negotiator, but also that for an expert to review murder cases involving Americans here.

But Long expressed little optimism over his apparent success at winning these concessions.

"I know that miracles don't happen overnight," he said, "and certainly not in El Salvador."

In a statement he read to reporters, Long said that Salvadoran President Alvaro Magana assured him after two meetings in the last two days that "the prisons and detention centers will be open to unannounced, unrestricted visits by the International Red Cross and that following early passage of the Amnesty Law thus far stalled in the constituent assembly substantial numbers of political prisoners, hopefully in the hundreds, will be released."

Despite an air of hard bargaining, much of Long's conditioning and maneuvering, as he described it at a breakfast this morning and later at the press conference, appeared aimed at saving aid for this country, rather than providing a pretext to cut it.

"There are many people who believe that the committee would probably vote against all foreign aid for El Salvador if we do not get some concessions of this kind," Long said, declining to discuss further the mood of his fellow Democrats who make up the committee majority.

Long accepts the scenario often presented by U.S. Ambassador Deane R. Hinton that an aid cutoff would lead, in Long's words to "a right-wing military coup, possibly followed by a bloodbath."

The Maryland congressman also said that while he has called for the appointment of a special envoy to bring the guerrillas into the political process through talks, he would not support the concession of any portion of power to the rebels except through elections.

The insurgents have said they are not interested in elections on those terms, which are essentially the same ones offered previously by the U.S.-backed government here.

"What I want to do is get a process going," explained Long, "something which once launched would in a sense be irreversible. That is the importance of naming a very high-level person as mediator whose reputation would be such that he can't have the rug yanked out from under him."

The congressman portrayed the problem of bringing the guerrillas to the bargaining table on the terms he described essentially as one of exerting enough force.

"What I've long favored is a carrot and stick approach. The carrot of course is a political solution. The stick is a military solution, and here I've urged that the military develop a real stick and not a wet noodle, which I think is what we've had in the past," Long said referring to the Army's persistent frustrations fighting the insurgents.

"I don't think the guerrillas, in other words, will ever come to a conference table and make agreements, until they feel they are not winning in the field," Long added.

But Long's frequent visits here--he now speaks of his "usual" rapport with President Magana--have provoked considerable resentment on the right.

"Attitude of the U.S. Congress is Condemned," read the lead headline of the daily La Prensa Grafica while El Diario de Hoy editorialized that "the country has been destroyed going from requirement to requirement."

To underscore his apparent progress in winning concessions on the issue of political prisoners, Long cited the release on Saturday and the scheduled release today of a total of 20 political prisoners. He said he was not aware of reports that at least as many have been incarcerated under sweeping emergency decrees in the same period.

There are currently about 800 political prisoners in El Salvador and Long himself noted that at least 15,000 people have been murdered by the security forces here in recent years.