Moscow — Barely four hours after President Reagan's conciliatory speech had been delivered Monday, the Kremlin had dismissed it as ''propaganda.'' ''Behind the loquacious rhetoric about adherence to limiting the arms race and love of peace was, in effect, the known position of the United States administration,'' said Tass, the official Soviet new agency.
''The whole speech,'' wrote Tass, ''is keynoted by the thesis about the need for the United States to build up its strength. All this shows that there is no indication of any positive changes in the Reagan administration's approach to the solution of problems of limiting and reducing arms, first of all nuclear ones.''
The Tass report was only five paragraphs long. And although the item was read on the evening newscast on Soviet television, it came after a number of other reports - including film footage of cattle at a collective farm. This was an apparent attempt to play down the importance of the President's speech for Soviet viewers.
The Kremlin was given an advance copy of the speech and therefore had ample time to mull it over. Still, some Kremlin-watchers expect a more detailed response to be issued in coming days. However, the tone for any subsequent response has apparently already been set - and it is hardly positive.
Western analysts do not expect that there will be any shifts in Soviet domestic or foreign policy as a result of Mr. Reagan's speech. Indeed, the Kremlin makes a determined effort to appear insulated from external pressure in the conduct of its affairs.
Nor is the Kremlin likely to take kindly to Mr. Reagan's references to continued disagreements over human rights. Emigration of Jews from the Soviet Union has slowed to a trickle under the first full year of Yuri Andropov's leadership. And Amnesty International continues to work on behalf of some 450 ''prisoners of conscience'' within the Soviet Union - persons imprisoned because of religious or political beliefs.
The Kremlin will likely contest Mr. Reagan's assertion that he favors a reduction in overall levels of nuclear weaponry. Pravda, in an editorial that came out on the morning of the President's speech, repeated earlier Soviet charges that American proposals at the Geneva negotiations on intermediate-range nuclear weapons would have allowed ''for the further quantitative and qualitative buildup of strategic armaments.''
Soviet officials have argued privately that they believe Mr. Reagan's more moderate approach to US-Soviet relations is a result of election-year expediency. However, some Soviet officials admit they simply cannot to refuse to deal with Mr. Reagan.
''We are not giving up on the Reagan administration,'' said a member of the Communist Party Central Committee before the speech.
''We are dealing with things that are not possible to wave away.''