A network storage system and a method for file caching are provided. The network storage system includes a first electronic apparatus and a server. The first electronic apparatus has a first storage space. The server has a network storage space larger than the first storage space. When the first electronic apparatus sends an access request to the server for accessing a first file within the network storage space, the server broadcasts a cache list in response to the access request. The cache list includes the first file and a plurality of neighboring file neighboring to the first file. After receiving the cache list, the first electronic apparatus accesses the first file according to the cache list, and caches at least one of the neighboring files according to a first cache space size of the first storage space.