Abstract: The interconnection mechanism for SDN network and traditional IP network has been the focus in academia, but the current solution can’t be used in every condition. To solve this problem, an architecture named IMISA was proposed which was based on the OSPF protocol. In the autonomous system with both SDN subnet (based on OpenFlow) and IP subnet, an OSPF routing module was added to the SDN controller to help exchanging network informations and finally the networks can communicate with each other.