Senior Polish officials said today there had been an improvement in the "psychological climate" in Poland as a result of what they described as "a restrained speech" by Soviet President Leonid Brezhnev and the ending of Warsaw Pact military maneuvers.

Brezhnev's remarks yesterday, while addressing the Czechoslovak Communist Party Congress in Prague, that Polish Communists would be able to "rebuff the enemies of socialism" was interpreted in official circles here as a qualified expression of confidence in the Polish leadership. This in turn has improved the atmosphere for negotiations between the Communist authorities and the independent trade union Solidarity.

Polish officals are aware of U.S. intelligence reports pointing to an increase in Soviet troops stationed around Poland's frontiers and the establishment of a communications and command network inside the country. But they said privately they did not regard this as a prelude to invasion.

Opinion is divided among Western diplomats here over the meaning of the latest Soviet moves. Some consider them another stage in a creeping invasion," while others believe that the Kremlin is still seeking to put pressure on the Polish leadership and people and is most reluctant to intervene directly.

Only future events will tell which explanation for the Soviet military buildup is correct. Particular attention will be paid to a speech Friday by the Polish premier, Gen. Wojciech Jaruzelski, to the legislature in which he expected to outline the government's intentions toward future negotiations with Solidarity.

The parliamentary session was originally to have been held last Monday, but was postponed with the excuse that Gen. Jaruzelski had a sore throat.

So far there is no evidence that the Polish authorities will feel constrained to take a tougher line with Solidarity. Indeed, the signs are that several protracted disputes, notably over demands by private farmers for registration of their own union, could be defense over the next few weeks.

Negotiations with the farmers, whose grievances were the indirect cause of the last government-worker confrontation, are now in the hands of a parliamentary commission with considerable discretionary power. Thus it is conceivable that a compromise will be reached on the issue despite the stated opposition of some Communist Party leaders, including the party secretary, Stanislaw Kania.

Meanwhile, a senior Polish official said privately that he had noted a marked drop in tension among the leadership following Brezhnev's speech.

"This has created the right psychological condition for talks with Solidarity. Key people in the party are now not so much afraid of Russian intervention," he said.

The official, who has close ties to several members of the ruling Politburo, added that he did not believe in the likelihood of Soviet invasion since the Kremlin "stands to gain more politically from non-intervention than from intervention." But he did not exclude other forms of political and psychological pressure.

A deputy member of the ruling Politburo, Roman Ney, described Brezhnev's speech as reflecting "an unchanged Soviet position toward the Polish crisis" which had been expressed on several previous occasions.

"This position is the firm belief that our party, together with progressive forces in Poland, can solve our problems by ourselves. I take this as the stand of Soviet Communists. They have confidence in our party," he said.

Officials here strongly discounted suggestions by some Western commentators that there was any significance in the failure of both Brezhnev and the Polish delegate at the Czechoslovak congress, Stefan Olszowski, to mention the name of Kania in their speeches. They noted that Kania, who has taken a consistently conciliatory line toward Solidarity was traveling to Gdansk Thursday for an important meeting with rank-and-file Communists at the Lenin shipyard.

"If this had happened 10 years ago under a different leader, it might have meant something. But Kania has preferred a collegial style of leadership and has never wished to push himself forward," an official said.

Some Western diplomats have expressed concern at what they described as a significant difference in approach between the Soviet and Polish leaderships. While Moscow clearly wants action to bring Solidarity under control, the Polish leaders are increasingly coming to realize that the only way of restoring peace to the country is to cooperate with the union.

But whatever the pressure from outside, inside Poland it is difficult to see how the Polish leadership can depart from the policy of dialogue and compromise without provoking a fresh crisis. One positive result of the tension of the past month has been to strengthen what is described here as "the front of reason and common sense."

As a reform-minded Polish official put it, "We now realize that politics has become too serious and dangerous a business to be left in the hands of extremists."

News services reported the following developments:

In Vienna, Austrian Chancellor Bruno Kreisky said visiting Soviet Premier Nikolai Tikhonov had dismissed as unwarranted Western fears of a Soviet invasion of Poland in their talks.

In Prague, Soviet President Brezhnev held informal talks with delegations from several "fraternal countries" and met with a top aide to Libyan President Muammer Qaddafi in the fourth day of his visit to the 16th Czechoslovak Communist Party congress.

Soviet attacks on Solidarity continued in Moscow with an article in the weekly Literturnaya Gazeta saying the independent trade union receives aid from West German "antisocialists," including former Nazis.