The highly publicized Soviet food shortage is most acute in big Russian cities and seems milder in the countryside, smaller cities and in non-Russian republics, a survey indicates.

"The situation is better here than in Russia," said Povilas Klimas, deputy mayor of Vilnius, capital of the Baltic republic of Lithuania, which declared independence in March. "We're ready to go ahead on our own."Officials from the 12 cities surveyed by The Associated Press said there was more food in farmers' markets than in state stores, although prices were higher. They blamed shortages on panic-buying and the collapse of the centralized distribution system, which is not getting the harvest into cities.

President Mikhail S. Gorbachev has appealed to the West for food to prevent winter unrest that he says may jeopardize his reforms. Foreign Minister Eduard Shevardnadze carried the plea Monday to Secretary of State James A. Baker III.

Gorbachev has said that much of this year's harvest has been diverted from the state distribution system and sold privately. He has called upon the KGB security police to make sure that Western food aid is not siphoned off.

An AP telephone survey found that food was plentiful in the Baltic republics and Central Asia, and scarce in Russia and two republics hit by ethnic unrest, Armenia and Moldavia.

The survey found little fear of starvation, in keeping with more thorough public opinion polls conducted by Soviet sociologists.

In a poll published this week in the weekly newspaper Moscow News, 27 percent believed that mass famine would commence this winter, compared with 57 percent who thought it unlikely.