James E. Dornan Jr.. 41, chairman of the politics department at Catholic University, died yesterday in an automobile accident on the George Washington Parkway in Virginia.

Park police said he was southbound on the parkway when he crossed the median strip near Gulf Branch and struck a northbound car, which in turn was struck by another northbound car.

Dr. Dornan was pronounced dead at Arlington Hospital. Police said an autopsy is being performed to determine the cause of death.

On the faculty of Catholic University since 1967, Dr. Dornan was instrumental in the reorganization of the politics department. He was an associate professor there, and was chairman of the university's Academic Senate.

A nationally known authority on U.S. foreign relations, military strategy and Asian affairs, Dr. Dornan was a senior political scientist with the Washington office of SRI International, a California-based research firm.

He was the author of a number of studies on national security matters and recently had conducted two studies for the U.S. Army -- "U.S. Strategy in Northeast Asia" and "Soviet Perceptions of the United States."

Dr. Dornan also had edited two books that were published recently -- "U.S. National Security Policy in the Decade Ahead" and "The U.S. War Machine."

He was born in Brooklyn, N.Y. A graduate of LeMoyne College in Syracuse, N.Y., he later earned a doctorate in political science from Johns Hopkins University.

Dr. Dornan taught at Purdue University from 1963 until coming to Catholic University.

He was a member of the American Political Science Association, the American Association of University Professors, the Academy of Political Science, the University Center for Rational Alternatives, the Arms Control Association and the United States Naval Institute.

He is survived by his wife, Diane and a son, Brendan, of the home in Hyattsville; five other children, James E. III, Patrick F., Kieran C., Erin and Meighan, all of Bowie, and his mother, Florence Dornan, and a brother, Dennis, both of Long Island, N.Y.

The family suggests that expressions of sympathy may be in the form of contributions to the Southeast Asia Resettlement Program of Catholic Charities.