Without explanation the Soviet government has denied entry visas to two American publishing officials who had planned to attend the Moscow International Book Fair, which opens next week.

Jeri Laber, a staff member of the Association of American Publishers (AAP) and executive director of Helsinki Watch, a nongovernmental group that monitors human rights violations, and Robert Bernstein, president of Random House and chairman of Helsinki Watch, were told by their travel agents that their visa applications had been denied. Bernard Levinson, president of the Association of Jewish Book Publishers, initially was denied a visa, but yesterday the Soviets reversed the decision.

The Moscow Book Fair began in 1977 as a biennial event, but the AAP has not participated since 1979, when the Soviets banned dozens of books, including George Orwell's "Animal Farm," all of Alexander Solzhenitsyn's works and a cartoon history of American foreign policy.

Laber said, "We stopped going for a number of reasons. There wasn't much commercial benefit for American publishers, visas were being denied with no explanation, there was censorship and, above all, we were deeply concerned about Soviet writers who have been arrested and thrown into prison. We thought with a new government in power, this would be a good year to test the waters again. But this puts a chill in the atmosphere."

The Moscow Book Fair was the center of some controversy in the spring when the AAP announced a list of 300 books published in the past five years "that reflect life in the United States." The National Endowment for Democracy, a bipartisan group financed by Congress, criticized the list as incomplete.

Other critics were more explicit, criticizing the list for not including more conservative titles. Some noted, for example, that while Seymour Hersh's critical biography of Henry Kissinger was included, Kissinger's memoirs were not.

In the end AAP funded its project without financial help from the National Endowment for Democracy and did not change the list. AAP will give away thousands of books at the Moscow fair.