Retired Air Forced Lt. Col. Robert W. Barnes, 61, an authority on military financial systems who helped organize the Air Force Accounting and Finance Center in Denver and who later joined the Federal National Mortgage Association, died of cancer Friday at the Walter Reed Army Medical Center.

Col. Barnes entered military service in 1942 and received his commission the following year. Durning World War II, he was a disbursing officer in the China-Burma-India theater.

After the war, he returned to this country, where he was assigned to the office of the chief of finance for the Army Air Forces and the Air Force here til 1948.

Col. Barnes then left military service for about three years. Durning that time, he was a senior sales representative for the Burroughs Adding Machine Co. here, where he specialized in government accounts.

In 1951, he was recalled to active duty and appointed chief of the records branch of the Air Force's accounting division. He was assigned to the then newly established Air Force Finance Center in Denver, where he was in charge of matters formerly handled at the Army Finance Center in St. Louis.

Col. Barnes also served as a special project offiecer for development of the Air Force's first automated military payroll system.

After his military retirement in about 1973, he became an administrative assistant in the loan accounting department at the Federal National Mortgage Association here.

Col. Barnes was born in Philadelphia. He graduated from Girard College, earned a bachelor's degree in business administration from Long Island University and master's degrees from Michigan State University and Benjamin Franklin University here.

He was a resident of Springfield for the last 14 years.

Survivors include his wife, Jean, Springfield; two daughters, Diana J. Green of Washington, and Patricia K. Beal of New York City; a brother, William A., of Potomac, and two grandsons.

The family suggests that expresions of sympathy be in the form of contributions to the American Cancer Society.