Marion Schell Kingsbury, 80, a pioneer in the field of remideal education and founder of the Marion Kingsbury Center for Remedial Education in Washington, died of pneumonia Monday at George Washington University Hospital.

Mrs. Kingsbury established the remedical education center in 1938 because no private facility of its kind existed in the Washington area at that time.

In its early days, the center was located in a two-room apartment in Northwest Washington, and Mrs. Kingsbury's staff included one psychologist, one tester-tutor and herself, a teacher trained to deal with reading and learning difficulties.

Today the center, a nonprofit, privately funded organization, includes a laboratory school, established in 1965, and treats about 1,000 persons a year, from preschoolers to adults. The center was named for Mrs. Kingsbury at her retirement in 1964. Its students are of normal or above-normal intelligence, but they suffer from special learning disabilities, including dyslexia, an impairment of the ability of read.

The center and labortory provide diagnostic testing, psychological and tutoring services and training for teachers and tutors working in public and private schools. Students are referred to the center by teachers, ophthalmologists and other doctors, and by parents. Cases of faulty vision and below-average intelligence are referred elsewhere.

While serving as director of the center, Mrs. Kingsbury helped develop two widely used visual aids used to develop students' reading skills. They were games patterned after dominoes and the children's card game, "Go Fish."

These games, as well as teaching manuals, are printed by the center's Remedial Education Press and profits from the books and game go to the center's scholarship fund.

After her retirement as director, Mrs. Kingsbury was a consultant for the center until her health began to fail several years ago.

She was born in Detroit and educated in this country and in Switzerland. She graduated from the University at California at Berkeley.

She met and married Slocum Kingsbury, now a retired architect, when she was living in New York City and working in amateur theater in Greenwich Village. The couple moved to Boston when Mrs. Kingsbury was offered a teaching job there, and it was there that she first became involved in teaching remedial reading.

At a retirement party for Mrs. Kingsbury at the Cosmos Club here, there was a man among the nearly 100 guests who wore a sign reading, "Mrs. Kingsbury's HUSBAND."

A 1976 leter from the president of the center's board of trustees, Helen S. Colson, to Mrs. Kingsbury read in part:

"Today almost everyone is aware of learning problems, but I know that 40 years ago your interest and knowledge were unique. There are today more than 20,000 families who are grateful for the center's help over the years. You must be proud of the institution you began and nurtured."

Mrs. Kingsbury was a charter member of the group that founded the Remedial Education Association, now the International Reading Association. She was a longtime member of the Sulgrave Club here.

She is survived by her husband, of the home in Washington.

The family suggests that expressions of sympathy be in the form of contributions to the Marion Kingsbury Center, 2138 Bancroft P1. NW.