Peter C. Goldmark Sr., 71, whose invention of the long-playing phonograph record revolutionized the recording industry and who was passionately concerned with using electronics for social progress, died in New York Wednesday in a car accident.

Dr. Goldmark, who was born in Budapest, Hungary, lived in Stamford, Conn. He was killed near Harrison. N.Y., while driving toward New York City, when his car struck another and spun around. He was thrown from the vehicle and fatally injured.

Creative, precise and prolific, Dr. Goldmark, who was likened to the "lone-wolf" inventors of the 19th century and who often in the spellof sudden inspiration, began work at his Columbia Broadcasting System Laboratory at 5 a.m. also was credited with developing the first practical color television system.

In addition, he was credited in the late 1960s with inventing a system of Electronic Video Recording (EVR), making it possible to play previously recorded material on a home television set. Such techniques are only now achieving widespread popularity among consumers.

Concerned both with the social problems he believe were created by misuse of technology for human progress, he served during the 1960s as head of the antipoverty office in Stamford.

Within two years after his 1971 retirement from CBS, he had persuaded the federal Department of Housing and Urban Development to under write what he called his "New Rural Societies" experiment, with two $362,000 research grants.

The system was based on plants to allow people in small towns to be linked electronically to entertainment, business, government and medical centers.

Dr. Goldmark, who received a Ph.D. from the University of Vienna in 1931, became entranced with television the same year. Using a kit sold by a British inventor, he put together the first television receiver in the Austrian capital.

"The picture came through in post-age-stamp size," he recalled. You could hardly make it out, it flickered so. It was also in color, all red," he added. "But," he went on, "it was the most exciting thing in my life."

It apparently was what led him a few weeks later to England, where he joined a radio campany, and set up a television engineering department.

Two years later, convinced that the future of television was not to be based in Britain, he sailed for the United States, and presented himself at the Radio Corporation of America.

RCA turned him down. With a gleeful lack of self-effacement that some have ascribed to his Hungarian heritage, Dr. Goldmark asserted: "This proved to be (RCA chief David; Sarnoff's biggest mistake."

Dr. Goldmark began work for CBS in 1936, soon becoming chief television engineer.

Three months after he was a 1940 screening of "Gone With the Wind," one of the first major technicolor films, Dor. Goldmark built a practical color television system, combining electronic technology with a mechanically rotated set of colour filters.

Eventually it led to one of the titanic corporate struggles of American industrial history, in which an RCA color television system, compatible with existing black and white sets, eventually captured the market.

Dr. Goldmark's system, highly praised for the pqualty of its image, eventually was used as the basis for TV equipment used by Apollo astronauts to send pictures back to earth.

The inspiration for the long-playing record came to Dr. Goldmark in 1945.

"I was at a part listening to Brahms being played by the great Horowitz," he said. "Suddenly, there was a click." In the middle of the music, the inventor recalled, came "the most horrible sound man ever invented.

The needle had reached the end of 78rpm record. "Somebody rushed to change records," Dr. Goldmark went on. But, "the mood was broken. I knew right there and than I had to stop that sort of thing."

Three years later, after listening to choruses of "it-can't-be-done," Dr. Goldmark did it.

In 1948, he and his team at CBS Laboratories introduced the LP record, which played for 22 1/2 minutes on each 12-inch side.

The new records, which revolutionized the entire recording industry, made use of a groove width of only .003 inch, compared with .01 for the old 78s.

Despite scoring some of the greatest successes in the history of American technology, Dr. Goldmark's career was not without setbacks and disappointments, and he had his detractors.

While some hailed him as the "lone-wolf" inventor, others termed him a dreamer, with emphasis on the intimations of impractically inherent in the word.

Of his scores of inventions, some failed, apparently because of what appeared to be his imperfect grasp of the realities of the marketplace.

In a memoir published in 1973, he suggested that his work - significant as it was in itself and developed to the extent it was by his employers - may have been even more significant in the degree to which it drove the rest of the electronics industry to extend the frontiers of progress.

Two weeks ago he received, along with 14 other scientists, the National Medal of Science from President Carter.

Survivors include his wife and six children.