An active safety apparatus for vehicles and a method of controlling the apparatus, which can actively control the operation of a safety device, such as an airbag device or a seatbelt device installed in a vehicle for restraining a passenger behavior and protecting a passenger in a vehicle collision, based on the conditions of a vehicle collision and the passenger behavior which vary depending on the conditions of the vehicle collision, thereby optimally protecting the passenger for the conditions of the vehicle collision and improving passenger safety of the vehicle.