The 23-year-old was acquired with pick three in the 2007 National draft, a selection secured courtesy of the Chris Judd trade with Carlton.
The East Fremantle recruit has already played 81 matches for the club he supported as a kid, and looks set to become an integral part of the Eagles midfield for many seasons to come.
"I’m really happy to have re-signed," Masten said.
"It’s nice to get it sorted early in the season, I really enjoy being around the boys."
After finishing seventh in last year's best and fairest, Masten had a career high possession tally in the Eagles 94-point demolition of Melbourne at the MCG last Saturday.
His 39 possessions against the Demons eclipsed his previous high of 38 touches against Port Adelaide in 2009.
“This is an exciting time at the footy club and hopefully we can build on last week’s win, particularly the second half. We really need to play four quarters of quality football," he said.
“It’d be good to do it against Carlton this week.”
After suffering groin problems in the early part of his career, Masten has blossomed into an elite runner and West Coast are hopeful he can take his game to even higher levels.
“We see Chris as an important part of our future,” West Coast list and contracts manager Craig Vozzo said.
“He is an emerging player who we believe will continue to improve.
“He has some great qualities and it is pleasing to re-sign him so early in the season.”
Masten has also become more damaging in the forward half. After managing just 17 goals in his first four seasons in the AFL, he kicked 20 from the midfield in 24 matches last season.
