Ellen E. Livingston, 71, a retired Library of Congress aide who played a key role in social security legislation, died Sunday at her home in Washington.

She had joined the library's Congressional Research Service at the end of World War II, and had served as a research analyst, assistant chief and then chief of the education and public welfare division until retiring in 1971.

In the late 1940s, Miss Livingston also served on the staff of the advisory council to the Senate Finance Committee. She assisted that committee and the Ways and Means Committee in social security laws.

When she retired in 1971, Sen. Russell B. Long (D-La.) stated on the Senate floor:

"Ellen Livingston's career and accomplishments stand as a model for present and future congressional research personnel. . . The social security laws and programs enacted over the years reflect her efforts and active participation in their formation."

At her death, Miss Livingston was working on a book on social security income limitations.

Born in Washington, Iowa, Miss Livingston was a graduate of Monmouth College in Illinois. She received a master's degree from the School of Social Work of the University of California at Los Angeles.

She worked with the Traveler's Aid Society in Los Angeles before coming here in the latter part of World War II, when she worked for the American Red Cross.

She is survived by a sister, Mrs. David Elder, of Washington, Iowa.