Franklin Q. Brown Jr., 75, an analyst with the Central Inteligence Agency for 20 years before retiring in 1967, died Friday in Suburban Hospital in Bethesda after a heart attack.

Mr. Brown came to Washington in 1933 to work for the old Public Works Adminstration. He was a railroad examiner with Reconstruction Finance Corporation in 1936 and then went to New York as a junior economist with an investment banking firm.

During World War II, he served with the Army Air Forces at the Pentagon and in Europe, returing in 1946 with the rank of colonel and the Legion of Merit. He joined the CIA a year later.

He was a member of St. John's Episcopal Church in Bethesda and did volunteer work at the National Cathedral. He was a member of the Chevy Chase Club.

Mr. Brown was a native of New York state and had made his home in Bethesda since 1942. He was a 1928 graduate of Harvard University and earned a master's degree in business administration there in 1930.

Survivors include his wife of 40 years, the former Beatrice Hutchinson, of Bethesda; four sons, Thomas E., of Norwich, Vt., Randall B., of Midland, Mich., James E., of New York City, and Charles T., of Piermont, N.H.; a daughter, Alice B. Lacey of Bedford Center, Vt.; a sister, Dorothy Hoar of Epping, N.H., and five grandchildren.

The family suggests that expressions of sympathy be in the form of contributions ot the National Cathedral.