Glasgow have secured Chris Fusaro, Ryan Grant and Duncan Weir on two-year contract extensions.
The three players have signed deals that tie them to the club until May 2014.
Head coach Sean Lineen told www.glasgowwarriors.org: "It was a priority for us to get these guys tied down early in the season. They've all really grasped the opportunity to become influential players for Glasgow Warriors, and the other coaches and I will be working hard with them to make sure they continue to fulfil their potential."
Scotland A flanker Fusaro, 22, joined the Warriors on his first professional contract last summer and has played a key role in the early stages of this season's RaboDirect Pro12 campaign.
The former Heriot's man said: "I've loved my time at the club so far, and have learned a massive amount from being around quality international players.
"We've got a young and hungry squad, and that's going to stand us in good stead for what should be a really positive phase in the club's development."
Former Edinburgh loosehead prop Grant, 25, said: "There's a real sense of common purpose in the Glasgow dressing room.
"I feel like I've been part of the group for a long time despite only having signed last summer, and I think that speaks volumes for the atmosphere and working environment."
Scotland A stand-off Weir, 20, said: "As a Glasgow boy through and through, I take huge pride in wearing the Warriors jersey and there's no better place for me to continue to come on as a player."