This paper introduces an adaptive cache proxy to improve the performance of web access in soft real-time applications. It consists of client proxies and cooperative proxy servers with a server-side pushing schema. The large amount of heterogeneous data will be stored in the proxy servers and delivered to clients through computer networks to reduce the response time and network traffic. The adaptive proxy pre-fetches and replaces heterogeneous data dynamically in consideration of networks cost, data size, data change rate, etc. The simulation results show that the modified LUV algorithm has better performance in terms of hit rate, byte hit rate, and delay saving rate. With the cooperative proxy caching, it is shown that the performance of the proxy caching system is more predictable even if the proxies need to deal with a variety of data. The modified adaptive TTL algorithm has better performance in terms of the combination of temporal coherency and system overheads.