An interest group-based P2P browser cache collaborative system, named IntraCache, is proposed in the paper. IntraCache is scalable, resilient to node failures and easy to manage nodes. In the system, the peers with similar interest are organized into autonomous group by PB grouping method and documents are located by similarity based search method. Trace-driven experiments show that PB-Grouping method can utilize local browser cache more efficiently than previous grouping methods. Even if using small cache size, PB grouping method can get preferable hit ratio. Moreover, the interest group-based search method can more efficiently prune the P2P search space and reduce the latency than previous search methods.