The defense team wanted to use the material to cross-examine Dr. Louis Pena, the coroner who concluded Lana Clarkson's Feb. 3, 2003, death at Spector's mansion was a homicide.
The defense has suggested it was a suicide. They said Clarkson's writings included accounts of her visions of a dead actress who shot and killed herself.
Superior Court Judge Larry Paul Fidler on Friday had indicated he likely would allow the material. But after reading the document during the weekend, he returned to court with a stern expression and indicated that what he found was so different from what the defense described that he checked to see if he had the right document.
Although the defense said its computer experts found that the document had been worked on or saved as recently as 2001, the most recent life story material in the document occurred 14 years before Clarkson's death.
Photos: Phil Spector Trial
The judge read aloud the passage about the dead actress, which showed Clarkson had found the account in a book about old Hollywood.
"I don't consider anything in this particular document to be significant," Fidler concluded.
Fidler said he would consider allowing the defense to introduce the material when it calls its own experts.
Spector, 67, the producer who rose to fame with the hit-making "Wall of Sound" recording technique in the 1960s, is accused of murdering Clarkson, whose body was found slumped in a chair in the foyer of his mansion.
Clarkson, who was 40, had met him for the first time at her job as a hostess at the House of Blues on the Sunset Strip. She was best known for her role in the 1985 cult film "Barbarian Queen."