The invention discloses a method for achieving path control applied in the system including circuit CS area and IP multimedia subsystem IMS area. The method comprises: it sets a path policy decision unit and path policy information in the policy decision unit; when the system checks the network received the calling user's calling/ conversation pleasing, it sends the checking information to the called HLR/HSS; when the HLR/HSS receives the path checking information, it captures the called path checking information from the policy decision unit; the HLR/HSS sends the path information to the checking network by the path decision; the checking network dose the call to the calling/ conversation by the path of the information note. It also discloses a system for achieving the path control.