Abstract: In a webbing tension device adapted for use in a seatbelt system for protecting an occupant in an emergency situation of a vehicle, comprising a wheel supported by a webbing takeup shaft, a pawl latched to the wheel to prevent the wheel from rotating and trigger means detecting an acceleration and deceleration acting upon the vehicle in the emergency situation thereof to release the pawl from the wheel, cam means is caused to abut on the pawl and the trigger means. Accordingly, the wheel is surely prevented from the rotation in an ordinary running situation of the vehicle, and in the emergency situation of the vehicle the trigger means moves the cam means to release the pawl reliably from the wheel. In the present webbing tension device, thus, latching and releasing performances between the pawl and the wheel are improved.