Moscow — The Kremlin is displaying an increasingly sophisticated grasp of the powers of public relations - both at home and abroad. Ten-year-old Samantha Smith of Maine got a taste of this new talent last month. Her letter from Yuri Andropov was read around the world . . . and the Soviet leader emerged with a fluttering of dove's feathers.
Propaganda, in the Soviet lexicon, is ''dissemination and explanation of ideas, doctrines, knowledge, and theories with a view to making them firm convictions of people.'' And that's what it's all about.
Abroad, the idea is to convince people that the Reagan administration - not Moscow, as Mr. Reagan says - is responsible for the arms race and for general world tension.
At home, under Mr. Andropov's six-month-old tenure as Communist Party leader, the focus has been to instill a new sense of efficiency and discipline in an economy nagged by their opposites.
The leadership has also gone to great lengths to convey to the Soviet people a new sense of Kremlin attention to their everyday needs and concerns.
The bid to spruce up Soviet propaganda is not utterly new, predating Mr. Andropov's elevation to the leadership on Leonid Brezhnev's passing. Mr. Brezhnev himself had called for efforts to make the news media far more ''convincing.''
With the advent of the new party chief, the campaign seems to have gathered steam.
One of the first personnel changes under Mr. Andropov was to replace the head of the party's domestic propaganda department.
The official Soviet press still prints a great deal of what, to the Western eye, is dry verbiage. The nation's evening TV news anchor man is apt to open the broadcast by reading a verbatim transcript of an official document or an Andropov statement, a rite typically followed by a report on the latest farm or factory stride toward activating the five-year plan.
Yet there have also been changes.
For one, the press has begun printing regular, if brief, reports of Politburo sessions - a practice unheard of in the Brezhnev era and, senior officials say, suggested by Andropov himself.
The Politburo reports have touched on a range of issues of keen interest to the ordinary Soviet: from the need to pay more attention to citizens' letters to the problem of ensuring more spare parts for automobiles or better housing in remote regions.
At one meeting, the press said, the Politburo moved to make roads safer. At another, it approved plans for production of a new Soviet passenger car.
Other Politburo reports have stressed the need for generally better economic performance - and the personal responsibility of citizens low and high for ensuring this.
At the same time, the Kremlin has streamlined its foreign affairs propaganda.
Reaction to various US decisions and statements has been announced with what, by recent Soviet standards, is remarkable speed.
Foreign Minister Andrei Gromyko, long a virtuoso public speaker abroad, summoned hometown and foreign reporters to his first Moscow news conference in more than five years - this to respond, with both articulateness and an occasional touch of dry humor, to the latest US arms control proposals.
Western diplomats suspect such events may become more frequent, in view of Mr. Gromyko's recent elevation to the additional post of deputy premier.
Moscow's Novosti news agency, which specializes in material for abroad, has issued a series of new, full-color pamphlets detailing Soviet arms proposals and targeting US ones. On the back of one booklet, a quill pen shaped like a dove flutters near the neat, cursive inscription: ''The Soviet Union is for negotiations, for limiting all types of weapons!''
And Andropov himself has lent a more personal approach to Kremlin dealings with the US.
While state-to-state ties remain strained, he used an interview last December to wish the American people a happy New Year.
And in April, he went further - in an avuncular, and literally disarming, reply to a note from young Samantha Smith of Manchester, Maine.
No, he assured her, Moscow would never contemplate war, nuclear or otherwise. And after a nice passing reference to Tom Sawyer, he invited her to visit the Soviet Union this summer for a first-hand look.
Samantha and her parents say they plan to go in July as guests of the Soviet government.