Dr. Allen S. Cross, 71, a retired Washington physician and former government official who developed an artificial resuscitation device in the mid-1950s, died of pneumonia Friday at the Veterans Administration Hospital in Martinsburg, W. Va.

He had been hospitalized in Martinsburg for the past four years after suffering a stroke.

Dr. Cross developed the "Venti-Breather" used for on-the-scene resuscitation of victims of drowning or electric shock. The instrument, which took years to develop, was perfected in 1958. It eventually was used by District fire and police forces as well as Pan American Airlines.

Dr. Cross maintained a private practice of general medicine on Capitol Hill for 25 years before joining the government in 1960. He was medical director at the Government Printing Office for about five years, then joined the D.C. Department of Public Health, where he worked until retiring in 1970.

He had served on the Commissioner's Urban and Renewal Council's conservation and rehabilitation committee, and had been an advisor to the Navy and Air Force on emergency respiratory resuscitation.

His professional memberships included the American Medical Association, the Medical Society of the District of Columbia, the Association of Military Surgeons, the Civil Aviation Medical Association and the National Resuscitation Society.

Dr. Cross was a native of Washington and a graduate of Eastern High School. He was president of the Eastern High Alumni Association from 1951 to 1953, and received that organization's Alumni Award in 1953.

He earned undergraduate and medical degrees at George Washington University. During World War II, he served in the Atlantic with the Army Medical Corps and attained the rank of major.

He was a Mason, and belonged to the Naval Lodge, the Scottish Rite and Almas Temple.

He was a resident of Washington.

Survivors incluse his wife, Gladys F., of Washington, and a daughter, Patricia Allen Murphy of Westminister, Md.