He's already written three books about Lyra and Will and their adventures, and now a fourth is on its way in October - called Lyra's Oxford.
The Times newspaper's website reports that you don't need to have read the other three books to understand this one.
The book will look a bit like a small bundle of material that has somehow slipped between Lyra's universe and our own.
David Fickling, the publisher, said: "This is one of the finest pieces of writing that Philip Pullman has produced."
The third book in the series - The Amber Spyglass - was named Whitbread Book of the Year last year, the biggest book award in the country.