Lloyd Symington, 71, a Washington lawyer who was active in civic, business and school organizations, died of cancer Nov. 18 at his home in Bethesda.

Mr. Symington served for more than 30 years on the board of directors of the National Symphony Orchestra Association. He was president of the board from 1968 to 1970, a period that included the orchestra's six-week strike in the fall of 1969. That dispute was finally settled after the directors threatened to cancel the season unless the musicians returned to work. Mr. Symington also served as chairman of the symphony board's executive committee from 1966 to 1968 and from 1971 to 1973.

Since 1946, Mr. Symington had practiced law in Washington, and at the time of his death he was a partner in the firm of Leva Hawes Symington & Martin. He was a graduate of Princeton and the University of Virginia Law School.

Mr. Symington served 20 years on the board of governors of St. Albans School and was chairman from 1955 to 1957. He was a member of the board of trustees of Potomac School and a director of the Levine School of Music in Washington.

Mr. Symington was also a director and general counsel to the Defenders of Wildlife, a former director of the Housing Development Corp., and a member of the American Bar Association, the D.C. Bar Association and the Federal Bar Association.

He was a member of St. Alban's Episcopal Church and active in Democratic Party politics. In 1968 he was a D.C. delegate to the Democratic National Convention.

Born in New York City, Mr. Symington was an associate with the law firm of Milbank, Tweed & Hope in New York before moving to Washington. He worked in the office of the general counsel of the War Production Board from 1942 to 1946.

Mr. Symington is survived by his wife, Nancy E. Glover Symington of Bethesda; three sons, Lloyd Jr., of Mill Valley, Calif., Nicholas, of Austin, Tex., and Donald, of Richmond; a daughter, Marion Werner, of Chevy Chase, and four grandchildren.