The 17-year-old, who has been linked with Liverpool and Manchester United, is yet to make a senior appearance for Fulham and was an unused substitute in the 2-1 home defeat to Swansea City on Saturday.
Jol believes Dembele is settled at the west London club, and has hinted that a contract extension beyond his current deal - which has two years remaining - could be in the offing.
|1/2||Fulham are 1/2 with Coral to survive in the Premier League this season|
"He's only 17 now, but he's strong and scores goals every match. I took him up to the Under-21s already.
"The boy loves it here. The only thing we've got to do is in the next couple of years to keep him here."
Dembele, capped at under-17 level for France, joined Fulham from Paris Saint-Germain and has risen to prominence with his prolific goalscoring form in the youth-team ranks at Craven Cottage.
The Frenchman netted five goals in his first four games for the Under-21s side.