Chief Keef was arrested for the SECOND TIME IN 7 DAYS yesterday ... when cops in Illinois say the 17-year-old rapper was doing 110mph ... in a 55 zone.
Law enforcement says ... cops spotted Keef's 2011 BMW X6 M flying down Winnetka Road in Northfield, IL around 3:45 AM.
When cops pulled the car over ... Keef was in the driver's seat with 3 passengers -- big problem, since Keef only has a permit which allows him to have ONE passenger.
After Keef was taken into custody, the BMW was released to one of the passengers ... who left the scene with the vehicle.
Keef was cited for speeding and having too many people in the car. He's due back in court on June 17.
The arrest comes exactly ONE WEEK after he was busted in Georgia for smoking weed at an Atlanta-area hotel.