Abstarct: Content caching at small baxse stations and around users is a promising and efficient way to reduce the effects of traffic growth on wireless networks. In this thesis, we focus on performance analysis of content caching in the two-tier heterogeneous cellular network. A heterogeneous cellular network is including the set of macro baxse stations and small baxse stations with different transmission power levels, the main purpose of which is to reduce the distance between users and baxse stations, as well as increase the speed and the probability of successful access to the content. In this thesis, the baxse stations are distributed according to the Poisson point process and user requests are baxsed on content popularity, which is modeled according to the Zipf distribution. The innovation of proposed system model is the cooperation between baxse stations, in order to deliver the content to the user. In the other words, the Applicant user will never connect directly to the macro baxse station and the content is always provided to the user via the small baxse station. Therefore, in order to performance analysis of proposed system model, we obtain the average outage probability in a closed form. Also, assuming that the communication between the network nodes is baxsed on the automated repeat request method, we obtain the average delay experienced by the user in a successful transmission of content in a closed form. Finally, using the obtained simulation results in the proposed system model, we illustrate that by increasing the popularity of content and also increasing the density of small baxse stations, the average outage probability and average delay experienced by user decreases.