Abstract: As for the interest flooding attack in Content-Centric Networking (CCN), this study proposes a new approach to mitigate interest flooding attack based on abnormal name prefix identification. This study utilizes the forwarding state in CCN routers to detect the interest flooding and identify abnormal name prefixes, and collaboratively defense the attack by sending the identified name prefixes to neighbors. Comparison between results of the proposed approach and others, the proposed approach is able to identify the abnormal name prefixes exactly, and quickly suppress malicious interest flooding without reducing the rate of normal interests.