Dissident Soviet authors Lev Kopelev and Vasili Aksyonov have been stripped of their Soviet citizenship while living abroad and thus permanently barred from returning to Russia, it was learned today. Authorities also revoked the citizenship of Kopelev's wife, Raisa Orlova.

An official of the Supreme Soviet, the national parliament, confirmed that its Presidium had issued the decrees, and said the Kopelevs had been punished for "systematically carrying out acts hostile to the Soviet Union" and damaging to the prestige of the nation.

Kopelev was informed by an official message that said, "You have been deprived of Soviet citizenship for slandering the high title of citizen of the U.S.S.R.," it was learned.

Sources said the decree against Aksyonov had been passed last Nov. 20 and against the Kopelevs Jan. 12, but neither had been made public. The decrees are to be published in the parliamentary proceedings of the Presidium later this month.

Aksyonov, 47, left with his wife and her children last July to lecture in the United States. He carried a Soviet international passport good for two years and applied for permission to leave only after receiving informal but official assurances he would not lose his citizenship.

The banning does not apply to his wife, Maya.

The Kopelevs left Nov. 12 for a year of teaching and lecturing in West Germany, where they are living with Nobel Prize-winning novelist Heinrich Boll. They had said they would return when their year was up, and had purchased return Aeroflot tickets.

Kopelev, 68, a burly, white-bearded scholar of German literature best known in the West for memoirs, suppressed here, of his nine years in Stalin's labor camps, was a major dissident figure in Moscow and close friend and supporter of human rights activist Andrei Sakharov. Orlova is a specialist in modern American literature and was expelled from the official writers' union for defending Sakharov after he was arrested and sent into internal exile a year ago today.

Each has two daughters by previous marriages. Three of them live here, while one of Kopelev's children, Maya, lives in Tarrytown, N.Y., with her husband, Pavel Litvinov, grandson of Stalin-era foreign affairs commissar Maxim Litvinov.

Aksynov, a physician whose tales of disaffected Soviet youth established him as an important contemporary writer of the Khrushchev "thaw" 20 years ago, clashed with authorities over the years, culminating two years ago when he helped organize the "Metropol" literary collection as a challenge to official censorship two years ago.

He later resigned or was expelled from all official groups and applied to emigrate last spring with his wife and her daughter, son-in-law, and grandson.

Aksynov is lecturing in Los Angeles and his wife's family has settled in Seattle, friends here say. Aksyonov's father, an Old Bolshevik who spent 18 years in the camps, lives in central Russia. The writer's son by a previous marriage lives in Moscow.