Comley, who is currently suspended after he was sent off at Newport, has made three appearances since joining the League Two club in January and the 20-year-old will now remain at Brunton Park until March 20.
"He's shown us exactly what we expected to see and he's taken the opportunity he's been given with both hands
He's added something different to the squad and he's enjoying his football," Blues boss Keith Curle told the club's official website.
"Last Saturday was another part of the learning curve for him and I know he's the type of character who will be better from having had that happen
You never want to take the edge out of your game but it's about how you implement it on the pitch.
"He likes a tackle, he likes to compete and he does a lot of work for the team
We're pleased that he's staying with us."
Comley has been at QPR since he was nine years old and made his debut for the then-Premier League club as an 80th-minute substitute on the final day of last season.
He played against Carlisle at Loftus Road in the Capital One Cup at the start of the current campaign.
Source : PA
Source: PA