Philip says a film company in New York is talking to directors and producers about putting his books onto the big screen.
"They are gradually putting the thing together but it does take a lot of time because films are very expensive things to make," Philip told CBBC Newsround in an exclusive webchat.
The Amber Spyglass is the third part of the His Dark Materials trilogy.
The novels tell the story of plucky heroine Lyra, her daemon Pantalaimon and her best friend, Will.
Together the three pals take on dark forces to save the world from destruction.
Find out what else Philip had to say by clicking on the link on the top right "Philip answers YOUR questions!"