An occupant restraint system of the present invention comprises a first sensor unit which detects a state of wearing a seatbelt system, a second sensor unit which detects a state of operating the seatbelt system, and a controller which performs a control to change a time range to determine activation and expansion of a occupant restraint equipment upon a vehicle collision in accordance with signals from the first sensor unit and the second sensor unit. In the occupant restraint system, when a state detected by the first sensor unit is a state of not wearing the seatbelt system, the controller performs a control to set a mode to a stopping mode which has a time range to determine the activation and expansion of the occupant restraint equipment upon a vehicle collision, and when a state detected by the first sensor unit is a state of wearing the seatbelt system and a state detected by the second sensor unit is a state of operating the seatbelt system, the controller performs a control to set the mode to an operating mode which has a smaller time range to determine the activation and expansion of the occupant restraint equipment upon a vehicle collision than that in the state of not wearing the seatbelt system.