In this paper, we investigate the optimization of content router deployment in large‐scale information centric core‐edge separation Internet. We formulate the target cost function, which captures the trade‐off between the cost for traffic transmission and cost due to additional deployment of content routers. To solve the problem, we first derive the analytical results of traffic ratio and its closed‐form approximation. We then construct a convex optimization problem, from which the optimal deployment probability can be solved. By extensive numerical results, the accuracy of the closed‐form approximation of traffic ratio is demonstrated. And, it is found that the optimal deployment probability is decided by the average number of hops for obtaining the content, the cost for traffic transmission, and the cost of extending router to content router. Copyright © 2013 John Wiley & Sons, Ltd.