The present invention relates to a file management method in a web storage system, and more specifically, to a file management method in a web storage system, in which when a user connects to the web storage system and creates, updates and stores files, files of a specific type are all deleted from a local PC and stored only in a file management system, and thus none of data is stored in the local PC.According to the present invention, when a file is created and stored using a web storage system, none of data related to a file that may cause a security problem remains in a user terminal of a remote site, and thus a file leakage problem may be cleared.