The invention discloses a device and a system to apply a control policy and a method thereof, meeting the demand to control multi-user operation with a same policy. The system includes a policy control and charging rules function (PCRF) and a policy and charging enforcement function (PCEF). PCRF sends an activation or setting command pointing to at least a control policy. PCEF includes: an acquisition unit to acquire an application range information of the control policy, and an enforcement unit which applies the control policy in a range that the application range information has pointed out when receiving the activation or setting command.