Milton Genderson, 63, owner and president of Genderson Chevrolet of Annapolis, died of a brain tumor Monday at his home in Annapolis.

Mr. Genderson began as a messenger in the automobile business for Ourisman Chevrolet in the early 1930s. He rose through the ranks and was a vice president and general manager at the time he resigned in 1972 to establish his own dealership in Annapolis. He recently opened a new eight-acre facility there.

A native of Baltimore, Mr. Genderson moved to Washington with his family when he was a boy. He was a graduate of Central High School here and later attended the Georgetown University School of Foreign Service. He lived in Washington until moving to Annapolis about a year ago.

He was a member of Adas Israel Congregation here and of Kneseth Israel Congregation in Annapolis.

He also was a member of the Samuel Gompers Masonic Lodge and the Norbeck Country Club, and a former member of the Basketball Referees Association and the Softball Umpires Association.

Mr. Genderson's survivors include his wife, Blossom, and a son, Barry R., both of the home in Annapolis; a daughter, Janet Zimberg, of Annapolis, and three grandchildren.

The family suggests that expressions of sympathy be in the form of contrbutions to a charity of one's choice.