Abstract: Multimedia proxy cache is an efficient technique to improve the quality of service of streaming multimedia and reduce network traffic. In this paper, a cooperated multimedia proxy cache architecture, MobileCache, is proposed for cell-based wireless environment. The proxies cooperate to provide seamless streaming for mobile clients. In order to improve the efficiency of MobileCache, a novel cache cooperation management scheme based on partition is proposed. Parts of each proxy’s physical cache space are organized in a large logical cache pool and managed centrally, which can take full advantage of the system cache resources and reduce the duplicates among proxies. To optimize the efficiency of the whole system, a global object placement strategy is introduced to manage the logical cache pool. The strategy can be modeled as an optimal problem and a modified genetic algorithm is presented to solve it. Simulation proves that the scheme and algorithm above improves the QoS of multimedia streaming, while startup latency and network transmission cost are notably reduced.