Lessing J. Rosenwald, 88 whose gifts of prints and drawings to the National Gallery of Art and of rare books to the Library of Congress have made their collections among the foremost in the United States, died Sunday at his home in Jenkintown, Pa. He had a bronchial infection.

Mr. Rosenwald began collecting prints in the mid-1920s. At that time, some of the great private collections of Europe were being broken up. Thus, he was able to buy works by such masters as Rembrandt, Albrecht Durer and William Blake that appear only rarely in today's art markets. He also bought modern works, so that his collection was noted for its breadth as well as its quality.

A few years after he began buying prints, Mr. Rosenwald began collecting rare books. He worked with Dr. A.S.W. Rosenbach, the leading book dealer in the United States in the 1930s, and his reputation soon spread so that he acquired the right of first refusal from most of the rare book dealers of the world.

He bought "The Giant Bible of Mainz," an illuminated manuscript that was produced in Mainz, Germany in 1452, the year the Gutenburg Bible, the first book printed with moveable type, was published. He purchased about a dozen blockbooks - books made on presess that used wooden blocks on which the letters were carved. He acquired about 600 examples of incunabula - books printed in the year 1500 or earlier. He bought modern books as well.

By the time of his death. Mr. Rosenwald's book collection numbered about 2,500 items. His collection of prints and drawings - the prints far outnumbered the drawings - included about 27,000 items.

The books have long since been the property of Congress. The prints and drawings were donated to the National Gallery of Art beginning in the 1940s.

"Mr. Rosenwald was the finest collector in the last 50 years in the field in which he was interested," Dr. Frederick R. Goff, the retired chief of the rare book division of the Library of Congress, said yesterday. "The Rosenwald collection is the great jewel in the Library of Congress collection."

Andrew Robinson, the curator of prints and drawings at the National Gallery, said, "Lessing Rosenwald formed what is probably the most comprehensive and finest collection of prints, drawings and illustrated books ever brought together by a single man in American."

By the terms of his gifts, Mr. Rosenwald's collection was kept on display during his lifetime at "Alverthorpe," his home at Jenkintown, eve though it belonged to the National Gallery or to the Library of Congress. But substantial parts of his collection always have been on display at the library or at gallaries here and elsewhere. Thus, his art has been available to the public as well as to students and specialists since Mr. Rosenwald began it.

"The Giant Bible of Mainz" has been on permanent display in the great entrance hall of the Library of Congress since Mr. Rosenwald donated it in 1952, when it was 500 years old.

It was understood that the Alverthorpe gallery would be closed and that the collection would be moved to Washington under the terms of Mr. Rosenwal's gifts.

Lessing Julius Rosenwald was born in Chicago on Feburary10, 1891. His father, Julius Rosenwald, was in the clothing business and in 1895 he bought 25 percent of the Sears, Roebuck Co. for $37,500. With the rise of the mail-order business in the United States, the elder Rosenwald made a fortune.

Lessing Rosenwald graduated from the University of Chicago and then went to Cornell University to study chemistry. In 1911, he joined Sears, Roebuck as a shipping clerk. He worked his way up through the company and was chairman of its board of directors from 1932 to 1939.

During World War II, he was director of the Bureau of Industrial Conservation in the War Production Board.

After the war, he gave all of his time to his art collecting and to the management of the family charities. The chief of these was the Julius Rosenwald Fund, which was devoted to improving interracial understanding. Mr. Rosenwald also founded the American Council for Judaism.

He said that he got interested in art when he noticed a print by D.Y. Cameron, a Scottish artist, in the window of a Philadephia print shop one day. He bought the picture, found himself interested, and began to read about prints and drawings. By 1929, he owned 4,300 prints.

He decided early in his career that he would donate his collection to the United States. This became the guiding principle in his buying: so far as was possible, he wanted to match the great collections of Western prints and drawings in the world. It was with a view to assembling a collection for nation that he went about his work.

He was one of the founding donors of the National Gallery when it opened in 1941.

Mr. Rosenwald's gift of incunabula to the Library of Congress complemented two other collecion - the Thatcher collection, which was donated in 1925, and the Vollbehr collection, which was purchased in 1930 - to give the library one of the best collections of these early books in existence.

Mr. Rosenwald continued to collect until the 1970s.

He was a former president of the Prince Council of America and a trustee of the National Gallery.

Mr. Rosenwald's survivors include his wife, the former Edith Goodkind, of the home in Jenkintown; two sons, Julius R. II, of Elkins Park, Pa., and Robert L., of New Hope, Pa., three daughters, Helen R. Snellenburg, of Philadelphia, Mrs. Isadore M. Scott, of Meadowbrook, Pa., and Mrs. Bernard Becker, of St. Louis, Mo.; 19 grandchildren, and 20 great-grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to a charity of one's choice. CAPTION: Picture, LESSING J. ROSENWALD