Internet requirements have dramatically transformed from data communications between two hosts to accessing a large amount of content. Given this fact

CCN becomes the hot spot to meet the new internet requirements in the next generation of Internet architecture. One common and important feature of CCN is to leverage in network caches to improve the transmission efficiency of receivers obtain content and network resource utilization. Firstly

this paper presents the basic idea of CCN

from two views of content cache replacement strategy and content caching decision strategies in CCN

how to realize the content caching of CCN in the existing research are presented. Secondly

this paper analyzes and evaluates the existing caching strategies. Finally

several key issues in CCN are discussed and future directions are pointed out.