It's not unusual for Peking and Moscow to like the same candidate in a United States election. But this year something is different - the Soviet Union and the People's Republic of China appear to prefer different candidates - China favoring President Reagan and the Soviet Union ''anybody but Reagan.''
The Chinese favor Reagan because they seem certain he will win. They can do little to influence the American voter and fear they might create a backlash if they try to get the President unseated. (The Chinese are very sensitive to foreign countries trying to affect their domestic politics, so this is understandable.)
Communist Party Chairman Deng Xiaoping is happy with his relationship with President Reagan. He is getting the most important things he wants from the United States - trade, technology, and ''aid.'' The Reagan administration has been quite generous with these.
Mr. Deng didn't have a high opinion of the Carter administration and no doubt identifies Walter Mondale with Carter's policies. Deng was, of course, happy about President Carter's decision to grant diplomatic recognition to Beijing (Peking). But he was furious when President Carter led him to believe the US would support China's decision to attack Vietnam in 1979 to teach Hanoi a lesson - which the Carter administration publicly decried as ''regrettable.''
Deng identifies the Reagan administration with free trade and Mondale with protectionism. The choice is clear for the Chinese: Trade will increase under a Reagan administration and likely will decline under Mondale. Since China needs access to US markets to keep its modernization program on track, Deng favors Reagan.
Finally, China supports a bigger defense role for the US. Deng still fears Soviet military expansion. There are 52 Soviet divisions on the Sino-Soviet border. The Kremlin, in Deng's view, is trying to contain China. The evidence is abundant: Moscow's bases in Vietnam, its funding of Hanoi's occupation of Kampuchea (Cambodia), its stepped-up war in Afghanistan to China's west.
Quite in contrast to Beijing's perspective, Moscow has openly saif that it won't do anything to help Reagan get reelected. Its refusal to discuss arms control and the Soviet walkout from the Olympics illustrate this point.
The Soviets seem to think that President Reagan can be defeated and that they can have some influence on the election. They perceive that the arms race will be a big issue in November and on that Reagan is vulnerable. And they think the Kremlin will not be blamed for the fact that talks are in suspension - a lesson they learned in Europe in their efforts to forestall deployment of new NATO missiles.
The Kremlin is bogged down in Afghanistan and needs to keep the attention of the Soviet people diverted elsewhere - they need an enemy. Contention with the US accomplishes this and justifies policies that might otherwise be difficult to explain.
Soviet leaders probably believe Ronald Reagan is the reason world public opinion is growing more hostile to the Soviet Union. President Reagan, more than any other president since the beginning of the cold war, has used his office to bring into sharp focus the Soviet Union's misdeeds: Afghanistan; the KAL Flight 7 airline disaster; Poland; the oppression of political dissenters in the USSR; forced labor; psychiatric prisons. The Soviets don't like being exposed before the world.
Moscow doesn't want to ever give the impression that the US ''China card'' works. Soviet leaders want to show the US and the world that improved US-China relations will not influence their foreign policy. Their dropping out of the Olympics - which coincided with the cancellation of a scheduled visit to Beijing by Soviet First Deputy Premier Ivan Arkhipov - is clearly as much a response to Reagan's China visit as it was to the Carter administration's boycott of the 1980 Moscow Olympics.
Since public opinion polls show that Americans feel more hospitable toward the People's Republic of China than the Soviet Union, President Reagan would appear to be helped more than harmed by the lineup just described. Just as well for the Democrats to stay out of this one; Moscow's vote certainly wouldn't help.