Soviet President Konstantin Chernenko failed to appear at a Kremlin election rally tonight, and the Soviet people were told for the first time that their leader is in poor health.

Chernenko, 73, was to make a traditional address on the eve of elections when his Politburo colleague, Viktor Grishin, announced that the Soviet leader would not attend the rally "on doctor's recommendation." In a nationally televised speech, Grishin said that he was asked by Chernenko to convey his "cordial greetings and best wishes" to the voters of his district and the people of Moscow.

For Soviet audiences, Grishin's reference to "doctor's recommendation" and the continued absence of Chernenko from public view suggest that the Kremlin chief is seriously ill.

Diplomatic observers here saw tonight's televised session as a signal that a new Kremlin transition is under way.

Chernenko was last seen in public Dec. 27.

The Soviet leader is said to suffer from circulatory difficulties connected with a chronic respiratory ailment. Some sources say he has asthma, while others describe his illness as emphysema.

There have been reports that Chernenko was hospitalized in early January, that at some point his condition was serious, but that he had recovered sufficiently to go to his dacha outside Moscow. He was officially reported to have attended a meeting of the Politburo on Feb. 7.

There have been subsequent rumors, however, that Chernenko had suffered a relapse and that he continues ailing at a hospital outside Moscow. The rumors could not be confirmed.

A senior Soviet spokesman earlier today confirmed, however, that the Soviet leader is still ill by saying, "He has the right to be ill like any other person. That's quite a natural thing." Tonight the president's speech to his constituents was read at the rally, according to Tass. The news agency did not say who delivered the address. Soviet television carried only speeches by Grishin and several other persons who support Chernenko's candidacy to the Supreme Soviet of the Russian Federation in Sunday's balloting.

As he delivered his speech, Grishin was flanked by Politburo member Mikhail Gorbachev, the second-ranking figure in the party hierarchy, and Foreign Minister Andrei Gromyko.

It was not possible to determine public reaction to tonight's announcement. In general, Chernenko's eight-week absence has created far less apprehension in official circles than did the similar conditions of his two predecessors, Leonid Brezhnev and Yuri Andropov.

The Soviet media has been depicting Chernenko during the past weeks as personally supervising the affairs of state. A series of statements, letters and interviews have been issued in the leader's name as well.

A similar pattern was followed during the last months of Andropov's life.

In the speech that was read in his name, Chernenko assessed positively the achievements of his first year in power, spoke about plans for the economy and addressed the forthcoming celebrations of the 40th anniversary of the end of World War II in Europe.

Chernenko appealed to President Reagan to join him in reaffirming postwar commitments to good relations between the Soviet Union and the United States and called for revival of the spirit of cooperation that marked allied relations in the struggle against Nazi Germany.

In marking the 40th anniversary, Chernenko said, "The leaders of the Soviet Union and the United States could jointly reaffirm in a form suitable to both countries the essence and spirit of the main commitments undertaken by both countries at the end of the war and in the agreements reached in the 1970s." He said the main thrust of allied agreements at Tehran, Yalta and Potsdam "remain topical today."

Before the resumption of U.S.-Soviet arms control talks in Geneva next month, Chernenko restated Moscow's view that Washington is not prepared to negotiate sincerely, especially on the issue of curbing the arms race in outer space.

But he called on Reagan to approach the Geneva talks "seriously and in good faith" adding that "agreement is absolutely necessary and quite possible" despite gloomy predictions.

The Soviet leader also touched upon Moscow's relations with Peking, saying that these are improving gradually.

In general, the speech did not break any new ground. In the view of western diplomats, it seemed designed to portray Chernenko as being at work and running the country.