Abraham L. Kaminstein, 65, retired register of copyrights at the Library of Congress, died Saturday at Sibley Memorial Hospital after a stroke.

As head of the Library's copyright office from 1960 until retiring in 1971, he had played a key role in putting together the new U.S. copyright status, which was passed in 1976. Most of its provisions take effect at the start of next year.

Work first began in the mid-1950s on revision of the copyright law. which hadn't changed much since 1909. It originally had been enacted in 1790.

When he became involved, Mr. Kaminstein noted that despite amendments, judicial interpretation and business practices that grew up around the law, was "uncertain, inconsistent or inadequate in application to presend-day conditions."

He pointed out: "Commercial radio and television were unknown in 1909. Motion pictures and sound recordings were in a rudimentary stage. New techniques for reproducing printed matter and recorded sounds have since come into use. These and other technical advances have brought in new industries and new methods for the reproduction and dissemination of the literary, musical, pictorial and artistic works that comprise the subject matter of copyright. And the business relations between creators and users of copyright materials have evolved into new patterns."

Mr. Kaminstein presided over numerous meetings of a panel of consultants. He participated in extensive testimony before Congress regarding revised copyright law.

The new bill enacted by Congress was designed to cover modern needs. Although it was not passed until after Mr. Kamenstein's retirement, it was in its major features, the measure prepared under his direction.

Mr. Kamenstein also participated in international copyright affairs. Over the years, he was U.S. representative at various session of the Intergovernmental Copyright Committee, established under the Universal Copyright Convention.

He helped to resolve the controversies between developing and developed countries over international copyright. He was chairman of the U.S. delegation to the International Convention for the Protection of Performers, Producers of Phonograms and Broadcasting Organizations held in Rome in 1961.

Born in New York City, Mr. Kamenstein was a graduate of the City Colege of New York. He earned bachelor's and master's degress from Harvard Law School, where he was a research fellow in 1936-37.

After serving as an attorney for several federal government agencies, he joined the Library of Congress in 1947 as chief of the copyright examining division and later was deputy register of copyrights.

Mr. Kamenstein was the author of numerous articles on copyright law, including a study on "Divisibility of Copyrights"

He was a member of the New York Bar and admitted to practice before the U.S. Supreme Court. He belonged to the Federal Bar Association, the American Bar Association and the Copyright Society of the U.S.A.

After his retirement, he became an honorary consultant in domestic and international copyright affairs at the Library of Congress.

In 1971, Mr. Kamenstein received the Richard Strauss Medal from the German Society for Performing and Mechanical Rights in Music.

A year later, he received the Jefferson Medal of the New Jersey Patent Law Association. Earlier this year, he was given the 1977 Award of the Copyright Society of the U.S.A.

He is survived by his wife, Barbara Kamenstein, of the home in Bethesda, and a son, Dana Seth Kamenstein, of Philadelphia.

The family suggests that expressions of sympathy may be in the form of contributions to the Copyright Society of the U.S.A. in New York City.