Retired Navy Lt. Cdr. Kenneth Harper, 56, who had been an administrative officer for the Defense Intelligence Agency, died of cancer Thursday at the Bethesda Naval Hospital.

Cmdr. Harper was a native of Independence, Mo., and attended the University of Missouri at Kansas City.

He served as a Naval flight instructor during World War II, and attended the Naval Air Intelligence School here in 1961 prior to his assignment to the DIA. He retired from the Navy in 1969.

Cmdr. Harper worked for RCA Computer Systems for three years, then joined the Association of State and Territorial Health Officials, a private organization of national health officials, in 1972. He worked for the Association as executive officer of its National Public Health Program Reporting System, until retiring forreasons of health in July, 1978.

He was a member of the National City Christian Church in Washington.

Cmdr Harper belonged to the Army-Navy Country Club, the Retired Officers Association and the Disabled Veterans Association.

He is survived by his wife, Helen K, and a daughter, Joan, of the home in Arlington; another daughter, Janet Flores, of Mojave, Calif.; two sons, Douglas and Gary, of Provo, Utah; his parents, the Rev. and Mrs. Lyndon W. Harper, of Lees Summit, Mo.; two sisters, Ruth Burroughs, of Naperville, Ill, and Prudence Wyle, of La Jolla, Calif., and five grandchildren.