Frank H. Alston Jr., 64, an artist who had worked as a designer in the Army's Institute of Heraldry since 1956, died of congestive heart failure Tuesday at Provindence Hospital.

Mr. Alston had designed a number of medals and seals for the government, including the Distinguished Service Medal for the Air Force, the Congressional Space Medal and the seal of the old Energy Research and Development Adminstration. He also had designed the Army's Bicentennial Medallion.

He won a number of awards for his oil and landscape paintings, including the John Hope Purchase Award, first prize for oil painting from the National Arts Club during the 1940s, and was twice winner of the Washington Times-Herald art show during the 1940s.

Mr. Alston has exhibited works at the Corcoran Gallery, the Library of Congress, the Pennyslavia Academy of Fine Arts, La Revue Moderne des Arts in Paris and Government House, in Freetown, Sierra Leone.

He was born in Provindence, R.I. He earned a bachelor of fine artsdegree at the Rhode Island School of Designin 1937. He moved to the Washington area 30 years ago.

Mr. Alston was a member of a number of organizations, including the Men's Club International of the YMCA, the Friends Of Sierra Leone, and the fine arts committee of the D.C. Federation of Civic Associations.

Mr. Alston was a member of the Calvary Protestant Episcoopal Church in Washington.

He survived by his wife, Barbara H., of the home in Washington; a daughter, Linda A.Daniels, of Washington; a son, Frank H. III, of Columbia, MD., and one granchild.