The actress told Australia's Moviefix that she is reading the erotic novel, but was evasive when asked if she'd play Anastasia Steele on the big screen.
"I don't know yet, I haven't finished reading the book," Stewart answered.
Emma Roberts has expressed interest in the Fifty Shades of Grey film, saying: "I haven't read it, I don't even understand, but yeah, it sounds awesome. Anything racy, hot. Sure, let's get hot."
Lucy Hale and Ashley Benson have also both been linked to the role of Anastasia, while Selena Gomez said the movie would be too risqué for her.
Ian Somerhalder has also campaigned to play Christian Grey, but admitted this week he "probably" won't even get to audition for Fifty Shades of Grey.
Watch Kristen Stewart in a teaser trailer for The Twilight Saga: Breaking Dawn - Part 2 below: