BOSTON (AP) _ Mathematics, theoretical physics and oceanography are among the fields in which American scientists are likely to learn much from their Soviet colleagues during upcoming exchanges, according to a delegation of Soviet scientists.

The Soviet researchers were in Boston Sunday to describe current Soviet research at the annual meeting of the American Association for the Advancement of Science.

Seven administrators from the most prestigious Soviet science institutes answered a wide range of questions from reporters in a rare meeting with the press Saturday.

The researchers seemed relaxed, and they answered questions without hesitation, including difficult questions on Soviet development of a Star Wars defense system.

''The Soviet Union does not intend to develop a system like the United States is working on,'' said Andrey A. Kokoshin, deputy director of the Institute for USA and Canada Studies.

A few moments later, when another Soviet researcher demonstrated a flashlight-sized laser pointer of the type used by speakers to call attention to details on projected slides, Kokoshin elicited laughter when he said, ''This is our SDI (Strategic Defense Initiative).''

Asked about development of chemical lasers, which might be used in a missile defense system, Kokoshin said, ''They are not very promising, I would say.''

On Jan. 12, Frank Press of the U.S. National Academy of Sciences and Guriy Marchuk, president of the Soviet Academy of Sciences, signed a five-year agreement providing for scientific exchanges and cooperation.

Under the terms of that agreement, joint scientific workshops will be held during the next two years on such topics as vaccine development, earthquake prediction, planetary science, biotechnology and astrophysics.

Konstantin V. Frolov, vice-president of the Academy of Sciences of the U.S.S.R., said that mathematics, theoretical physics and laser and semiconductor technology are some of the traditional strongholds of Soviet science.

''The Soviet Union has developed a number of sophisticated scientific instruments,'' he said, speaking through a translator.

Computer software useful in oceanography has also been developed in the Soviet Union, he said.

In the upcoming scientific exchanges, he said, ''these are areas where the Soviet side could bring something to the table.''

He proposed that joint ventures be established to develop computer manufacture. ''There was quite a gap in the introduction of computers in the Soviet Union, particularly personal computers,'' he said.

Yuriy A. Ossipyan, director of the Institute for Solid State Physics, said that Soviet scientists had developed a new description of the interaction of materials in certain high-temperature superconductors. He said that research on superconductivity is being actively pursued at his institute and elsewhere in the Soviet Union.

In a presentation Sunday, Mikhail V. Ivanov, director of the Institute for Microbiology, said that the Soviet union has built industrial plants for the production of animal feed through yeast fermentation.

Bacteria are being used to leach metals from poor quality ores, to decrease potentially dangerous levels of methane gas in coal mines and to enhance oil recovery, Ivanov said.

Albert Galeev of the Institute for Space Research described the planned launch in July of a spacecraft to study the Martian moon Phobos, which may be an asteroid that got trapped in orbit around Mars.