Booth Mooney, 64, a close fried and biographer of the late President Johnson and author of a number of other books, died of cancer Tuesday at his home in Summer, Md.

In 1953, Johnson, who was then serving in the Senate, called Mr. Mooney to Washington to be his executive assistant and speech writer. Mr. Mooney served in that position until 1958. During that period, Mr. Johnson was Senate minority and then majority leader.

While working for Johnson, Mr. Mooney wrote the biography, "The Lyndon Johnson Story."

A slightly revised edition of it was published shortly after the assassination of President Kennedy in 1963, and was translated into more than 40 languages.

It was considered then to be the best immediate source of information on the life and character of the new President.

Born in Wise County , Tex., Mr. Mooney started writing for newspapers at the age of 13, when he covered county courthouse matters in Decatur.

During World War II , he was a captian in the Army Air Force. After the war, he opened a public relations firm in Dallas under the name of Mooney and Cullinan. The firm represented former Gov. Coke Stevenson in a hotly contested campaign for the Senate seat held by Johnson.

Johnson retained his seat but won by a margin of only 74 votes. He was so impressed however, by Mr. Mooney's handling of his opposition's campaign that he asked him to come to Washington.

After leaving Johnson's office in 1958, Mr. Mooney worked as a freelance public relations man. His clients included the late Texas oil magnate H.L. Hunt.

He wrote other books, "Roosevelt and Rayburn: A Political Partnership," and "The Politicians: 1945 to 1980."

He also published two paperback novels, "Here Is My Body" and "The Insiders," a story based on Washington influence peddlers.

Mr. Mooney was the author of a pioneer work on food additives. "The Hidden Assassins." His last book, "LBJ: An Irreverent Chronicle," an appraisal of the late President, is currently on the stands.

Mr. Mooney was a member of the Metropolitan Club and the Kenwood Country Club and a former member of the National Press Club.

He is survived by his wife, Elizabeth Comstock Mooney, and a daugther, Joan, of the home; a son, Edward, of New York City, and three brothers, Orus of Austin, Tex.; Dan, of Decatur, Tex., and Fred, of Duke, Okla.

The family suggest that expressions of sympathy be in the form of contributions to the Veterans Administration Oncology Branch at the National Cancer Institute.