Abstract: The present invention relates to an adjustable seat belt guide (15) which is constructed of a clamping belt (5) around the back support (6) of a car seat (4) in a vertical way and supplied with a tightening retaining clip (7) for a taut fastening, in which through a cover (8) around the clamping belt (5) a rectangular carabiner or other inventable locking mechanism (10) provided with a lockable opening, preferably a turnable bush (11) is attached, in which the car seat belt (1) is applied through the locking mechanism (10) so that a very comfortable complete car seat belt assembly is created for a pleasant ride.