A cache memory system is provided. The cache memory system includes multiple upper level caches and a current level cache. Each upper level cache includes multiple cache lines. The current level cache includes an exclusive tag random access memory (Exclusive Tag RAM) and an inclusive tag random access memory (Inclusive Tag RAM). The Exclusive Tag RAM is configured to preferentially store an index address of a cache line that is in each upper level cache and whose status is unique dirty (UD). The Inclusive Tag RAM is configured to store an index address of a cache line that is in each upper level cache and whose status is unique clean (UC), shared clean (SC), or shared dirty (SD).