Raymond E. Cox, 84, a retired Foreign Service officer and president of the National Symphony Orchestra during 1949-51, died of pneumonia Friday at Washington Hospital Center. He had suffered from emphysema.

Mr. Cox had been a Washington resident since retiring from the Foreign Service in 1946.He had been a member of the orchestra's board of directors from 1949 to 1968.

He joined the State Department in 1921.After serving as a Foreign Service officer in Peru and Washington, he was assigned in 1925 as an aide to Gen. John J. pershing on the Tacna-Arica Plebiscitary Commission in South America.

Mr. Cox subsequently was assigned to diplomtic posts in England, Argentina, Czechoslovakia, Norway, New Zealand and France. He also served with the U.S. delegation to the United Nations.

He was born in Boston and graduated from Yale University in 1915. During World War I, he held the rank of captain in the U.S. Army infantry and participated in some of the major campaigns in France.

Mr. Cox was a member of the Metropolitan, Alibi and University clubs here.

He is survived by his wife, Margaret Berwind Cox, of the home; a son, Alan B. of Washington, and three grandchildren.

The family suggests that expressions of sympathy may be in the form of contributions to the National Symphony Orchestra.