MOSCOW (AP) _ Following are brief sketches of the Soviets expected to join Communist Party chief Mikhail S. Gorbachev at this week's summit meeting with President Reagan in Geneva:

EDUARD A. SHEVARDNADZE - A newcomer to superpower diplomacy, Shevardnadze was named in July to replace Andrei A. Gromyko as foreign minister of the Soviet Union. He also was promoted to full membership in the Communist Party Politburo, the 12-man body that rules the nation. The 57-year-old Shevardnadze made a strong impression on diplomats and journalists during visits this year to Helsinki, Finland, and the United States. But his background before joining the top ranks of Soviet leadership lay far from the diplomatic world, in the police and party organs of his native Georgian republic.

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ANATOLY F. DOBRYNIN - This 66-year-old career diplomat is the doyen of the Washington diplomatic corps, where he has served as Soviet ambassador since 1962 during six U.S. administrations. Dobrynin, a member of the party's Central Committee, has become one of the key players in U.S.-Soviet relations, taking a more active role than the American ambassador in Moscow. Although Dobrynin is not known as an arms control expert, he played an important liaison role in finalizing negotiations on the 1979 SALT II treaty and has negotiated with Americans on everything from bird migration to the status of Berlin.

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GEORGY A. ARBATOV - Head of Moscow's Institute for U.S.A. and Canada Studies, Arbatov is reputed to be the top Kremlin adviser on U.S.-Soviet relations. An articulate debater, Arbatov often presents the Kremlin's view on superpower issues in television interviews. The 62-year-old is also a Central Committee member.

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GEORGY M. KORNIENKO - Kornienko has long experience in U.S.-Soviet affairs, having headed the American desk at the Soviet Foreign Ministry before being appointed deputy foreign minister 10 years ago. The 60-year-old Kornienko, who also holds a seat on the Central Committee, has frequently been called upon to present Kremlin statements on arms control and has given several news conferences on the subject over the past few years. More affable than many of his colleagues in the Foreign Ministry, he likes to use English-language expressions he has picked up over the years.

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VIKTOR P. KARPOV - The 57-year-old Soviet envoy heads his country's overall delegation to the Geneva arms control talks as well as its negotiating team on strategic weapons. He entered superpower talks as a member of the Soviets' SALT I team in 1969. He was also part of the Soviet group that hammered out the SALT II agreement, and was delegation chief for Moscow during the last year of those talks. In 1982, Karpov became leader of the Soviet team at the strategic arms talks in Geneva, known in the United States as START. Those talks were broken off in November 1983 after the Soviets walked out from parallel negotiations on reducing medium-range rockets in Europe. A career diplomat with 14 years at the Soviet Embassy in Washington, from 1952-66, Karpov is considered an expert on the United States and a formidable negotiator.

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YULI A. KVITSINSKY - The Soviets' chief negotiator on space weapons at the Geneva talks, the 49-year-old Kvitsinsky has a reputation for tough bargaining that dates back to the talks leading to the 1972 four-power agreement on Berlin. He once served as deputy head of the Soviet Embassy in Bonn, where diplomats remember him as a protege of former Foreign Minister Andrei A. Gromyko and a key adviser to the Soviet SALT II negotiating team. Kvitsinsky became head of the Soviets' medium-range arms team when the original Geneva talks aimed at disarmament began in April 1981, and he was the Soviet participant in the abortive ''Walk in the Woods,'' when he and U.S. negotiator Paul Nitze tried to work out an acceptable compromise to the negotiations impasse that was rejected by their governments. Kvitsinsky was put in charge of negotiations on space weapons when the superpowers resumed arms talks in March.

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ALEXEI A. OBUKHOV - The 48-year-old Obukhov is in charge of the Soviet team negotiating controls on medium-range weapons in Geneva, and worked closely with Karpov during the START talks. A fluent English speaker, he is one of the four deputy chiefs of the Foreign Ministry's American department. Obukhov served as a counselor in the department in 1973-79 and was an attache at the Soviet Embassy in Thailand in 1965-66.

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ANDREI M. ALEXANDROV - This Central Committee member has been top personal aide to four Kremlin chiefs - Leonid Brezhnev, Yuri Andropov, Konstantin Chernenko and now Gorbachev. The 68-year-old Alexandrov is considered to wield considerable influence behind the scenes, but rarely appears in public.

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LEONID M. ZAMYATIN - As head of the party Central Committee's international information department, the 62-year-old Zamyatin serves as the Kremlin's chief spokesman and oversees news conferences and much of the information distributed to Soviet and foreign news media in Moscow.

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BORIS P. YAKOVLEV - Chief of the Communist Party's letters department, Yakovlev is responsible for party and political correspondence. The 77-year- old has made a career of party work and was considered an ally of late President Konstantin U. Chernenko.