Poland's military ruler, Gen. Wojciech Jaruzelski, today promised some relaxation in strict martial law regulations by the end of February, but he made clear that stringent controls over the Solidarity trade union movement, including the detention of many of its leaders, would remain in force.

Addressing the Sejm, the national assembly, which met today for the first time since the imposition of martial law six weeks ago, Jaruzelski also harshly attacked the United States, accusing it of hypocrisy in pressing for sanctions against the Polish regime. He charged that Washington is using the Polish crisis to attempt to dismantle the basis of postwar security in Europe.

Secretary of State Alexander M. Haig Jr. and Soviet Foreign Minister Andrei Gromyko prepared for talks Tuesday in Geneva that are expected to be strained if the United States brings up the issue of Poland. The White House reacted coolly to Jaruzelski's speech, saying it "surely could not be characterized as positive in its implications." Details on Page A12

Jaruzelski's 100-minute speech had been billed by officials as a major policy declaration by the martial-law authorities. But it left many questions unanswered and provided few firm clues as to how the Communist regime plans to run Poland without the protective shield of the Army when it eventually ends martial law.

After his speech, in a rare scene in this Communist-ruled state's national assembly, a scattering of Catholic and independent legislators criticized the martial-law decrees, provoking outbursts and jeering that required the speaker of the Sejm to ring his bell to call for order.

Despite the dissenting voices, the parliament endorsed martial law retroactively with the leaders of all the major government parties--the Communists, the Democrats and the Peasants--speaking in favor of it. Warsaw Radio, which reported the outcome of the vote, gave no breakdown.

Jaruzelski, who holds the positions of prime minister and Communist Party leader, said that the ending of martial law would depend on the "fulfillment of conditions that would secure a permanent, safe and normal course of life, the smooth functioning of the economy."

He said those martial law restrictions that "are felt by all of society" were being gradually lifted.

"If there is no deepening in illegal activities," he said, "if there are no unforeseen circumstances, then we hope that these restrictions will be abolished or significantly limited by the end of next month."

He did not specify which martial law regulations he had in mind, but observers believed that he was referring to restrictions on travel within Poland, the overnight curfew and a blackout on telephone and telex communications between cities. Specific measures aimed against Solidarity, the suspended independent trade union, are expected to continue, including the suspension of all trade union activity.

Over the past few weeks, the authorities have allowed a resumption in local telephone calls, lifted censorship on foreign correspondents and shortened the curfew. Theaters and movies have been reopened in Warsaw and other major cities and some army units have been sent back to barracks.

Jaruzelski made it clear, however, that the ruling military council was not prepared to relax its political grip on the country. Among measures taken to prevent any open opposition to military rule was the decision to suspend the traditional practice of broadcasting the Sejm session live on television. Instead edited highlights of today's debates were shown later.

Some of the harshest passages in Jaruzelski's speech were reserved for a bitter condemnation of the economic and political sanctions imposed against Poland by the United States and its NATO allies. He said Poland has never "bowed down before a foreign ultimatum" and the only result of such actions would be to "lengthen and sharpen martial law."

"This is not going to break the resolve of the authorities," he declared to applause from the deputies.

Accusing the United States of hypocrisy, he said, "The government which has for years been torpedoing the imposition of sanctions on the great concentration camp which is the Republic of South Africa does not hesitate to impose sanctions on Poland. The head of the Polish government did not demand the release from American prisons of the handcuffed air traffic controllers trade union leaders."

Jaruzelski said that an attempt had been made to use the Polish crisis to "start tampering with the bases of postwar security in Europe as defined in the Yalta and Potsdam agreements." It was a consequence both of these agreements--negotiated by the Soviet Union, the United States and Britain--and of the postwar military situation that Europe became divided into separate spheres of influence or blocs.

"They did not manage to fulfill their goals before Dec. 13, so they are trying to achieve them now through a policy of threats, boycotts and sanctions," he said. He added that it was a matter of deep regret that the chief organizer of the campaign was the United States, "a country with which Poland has traditionally had friendly ties."

Jaruzelski insisted that the imposition of martial law had not been in response to pressure from the Soviet Union, as maintained by President Reagan. "It was our own decision, based on our own analysis and carried out with our own forces," he said.

The deputies applauded Jaruzelski when he reaffirmed Poland's friendship with the Soviet Union.

"Poland will return to its rightful place among the socialist states," he said, adding, "The basis of our policy has always been alliance with the Soviet Union. Let us learn to respect other nations if we want them to respect us. There will be no room for anti-Soviet outbursts, for megalomania or nationalism."

The impression among Polish and foreign analysts here is that, after successfully eliminating open resistance to martial law, the military regime still has no clear idea of how to go about creating a new national consensus. In particular, Jaruzelski gave no indication of what role Solidarity would be allowed to play in the future.

He said that the trade union movement in Poland should be "politically united" but he added that individual branches could be organized on "an independent, self-managing basis" as a counterweight to the bureaucracy.

Revealing differences within the ruling hierarchy over trade union policy, Jaruzelski said some people were "for pluralism of trade union structures" while others favored a single cohesive movement.

For now, the government's main concern is with public reaction to a package of planned price increases to be introduced Feb. 1. Jaruzelski today defended the increases, which average between 300 and 400 percent, as an essential condition for economic reform.

Price increases in 1970 and 1980 led to the fall of the government.

Jaruzelski promised to go ahead with political, economic and social reforms, including a relaxation in the country's passport laws that could result in a mass exodus of Poles.

He said that Polish citizens who had stayed abroad would be allowed back without being penalized for their past behavior.

"Let there be no wall erected between the homeland and our citizens abroad," he said.

Some scattered opposition to the martial law decrees was heard from Catholic and independent deputies following Jaruzelski's speech. Speaking for the five-man Catholic group Neo-Znak, Janusz Zablocki said introduction of martial law had been a cause for grief, not triumph.

There was a yell of "back to the church" from a Communist deputy when Zablocki said his group would not vote for the decrees.

"Contrary to what is being claimed, there is a mood of revenge and vengeance in some circles. Some people are taking advantage of martial law to settle accounts," he said.

Echoing concerns expressed by the Roman Catholic primate of Poland, Archbishop Jozef Glemp, Zablocki criticized requiring Solidarity activists to sign pledges of loyalty to the regime.

He also warned of the danger of underground activity by Solidarity supporters, a theme that was also mentioned by independent deputy Karol Malczuzynski.

Malczuzynski, a well-known Polish journalist, said that 60 percent of Poles were young people who had no memory of either foreign intervention or wartime occupation and there was a very real possibility they could turn to violence unless allowed to express their grievances in a peaceful way.

Malczuzynski was jeered when he said there were some people in authority who might grow to like martial law since it ensured that their orders were obeyed. He exempted Jaruzelski from his criticism but there was a yell of "You have no moral right to lecture the prime minister."

Jaruzelski's address came a day after Glemp, who has been playing the role of trusted intermediary in the Polish crisis, said in a televised broadcast that the Roman Catholic Church in Poland is working to lessen the suffering of Solidarity activists detained under martial law.

Glemp said Poles have the right to know the truth about what is happening in their country and should demand "honest information" from domestic and foreign news media.

Calling for national unity, Glemp said it could be achieved only in an atmosphere of dialogue between rulers and ruled and the condition for dialogue was respect for the truth.

"In the fervor of conflict, we must take care not to slander either the authorities or the citizens," he said. "We must not tell lies about them or exaggerate their errors or forget about their merits."

While the Jaruzelski regime is believed eager to acquire legitimacy by an accommodation with the church, it has also made clear that it will not tolerate significant political opposition.

An indication of this uncompromising mood was the dismissal Saturday of Ryszard Reiff, the sole member of the State Council who voted against introduction of martial law, from his post as head of the pro-government Catholic organization Pax.

Earlier Pax was among several lay Catholic organizations suspended under martial law regulations. But the authorities allowed the management board to meet this weekend after engineering an anti-Reiff majority.

The newly elected management board promptly criticized Reiff's attempts before martial law to promote the idea of power-sharing among the Communist Party, the Catholic Church and Solidarity.

Western analysts believe that Reiff will soon lose his post on the State Council as well but this requires a Sejm vote. Reiff was replaced as head of Pax by Zenon Komendar, the minister for internal trade.

The taming of Pax means that the regime has eliminated most potential sources of political opposition to martial law. The strongest moral opponent to the crackdown remains the Catholic Church, which, however, is taking care not to provoke an open confrontation with the authorities.

Another sign of toughness toward would-be reformers came with the dismissal Saturday of the provincial governor of Gdansk, Jerzy Kolodzejski, who helped negotiate the agreement with striking workers in August 1980.