Benjamin Levich, a prominent Soviet scientist barred from emigrating to Israel, said today that the Kremlin is trying to intimidate and slander him because it fears that other Soviet scientists are rallying to his cause.

Levich, who was denounced by the official Literary Gazette last week, called that denunciation and other attacks on him a response to activities in his behalf by Soviet colleagues.

When a three-day conference was held at Oxford University last month honoring Levich's scientific accomplishments, at least five members of the prestigious Soviet Academy of Sciences sent letters expressing support and good wishes. Levich was denied permission to leave the Soviet Union to attend.

The physicist, the highest-ranking Soviet scientists to apply for permission to emigrate to Israel, said that in addition to the Literary Gazette attack, he has received anonymous threatening telephone calls and some of his friends have received letters slandering him.

He noted that the Literary Gazette denunciation was read in English last night on Moscow radio and said this was proof of the seriousness of the campaign against him.

The Literary Gazette accused Levich of plagiarism, incompetence and defamation of his homeland. It labeled the Oxford conference, which drew 19 Nobel Prize laureates, "an organized anti-Soviet action on an international scale" and "a pro-Israel-smelling plot."

Levich complained last month that his requests to attend the conference - sent to Communist Party leader Leonid Brezhnev - were unfairly denied; today he called the Literary Gazette attack "something very serious . . . slander and blackmail . . . an ominous sign."

Levich, at a press conference at his apartment, said the attack left him no choice but to respond to defend himself. He said he has written an open letter to the Literary Gazette, the weekly publication of the official Writers', Union. "Experience has shown that similar articles as a rule pave the way to grave reprisals," he said.

The Gazette said a former colleague of Levich, Yakov M. Kolotyirkin, said Levich had quit his research work in 1972 "though he could have continued at the same institute and could have published his work."

Levich says he was dismissed from both his directorship of the Institute of Physical Chemistry and his chair at Moscow State University when he applied for a visa to emigrate to Israel. He has been out of work since, attempting to continue his research in his apartment, where, he noted today, he has no access to a computer, essential to his field, the study of hydrodynamies.

The newspaper accused Levich of signing his own name to the research papers of subordinates and said he had published nothing useful in the past eight years. In fact, Levich says, he has had papers published outside the Soviet Union. He cited as an example a 65-page paper he submitted to the Oxford conference. The paper, read on the opening day, was called a "masterpiece" by Dr. I. I. Glass, associate director of the Aerospace Institute of the University of Toronto.

Levich declared drily, "I don't know that my paper was a masterpiece. The masterpiece was to have it get there." He said he unsuccessfully sent a copy of it through Soviet mails. The copy read at the conference apparently got there some other way.

In his open leter, Levich charged the Literary Gazette with failing to report that "For 2 1/2 years my wife and I have been separated from our children who left this country trusting official assurances of our being reunited soon." In 1974, during President Nixon's second trip to the Soviet Union, Levich and his two sons were promised that their long-delayed visa applications would be acted upon quickly and favorably. Only the sons have been allowed to leave and now live in Israel.

Although more than 110,000 Jews have been allowed to emigrate from the Soviet Union in the past few years, a small but significant number have been denied exit visas. Many of these are scientists and have been told by Soviet authorities that they cannot leave because they were privy to sensitive information.

Levich falls into this category, although he says he was told by officials in 1974 that while he had done some sensitive work it was so long ago - more than 20 years - that he was not going to be refused on those grounds.