Document collaborating method among multiple users

A document collaborating method among multiple users, comprising following steps of:

• (a) for each user creating one or more types of message accounts correspondent to a username of the user, wherein each user is able to establish contacts and a collaborative group thereof;
• (b) allocating a document initial version number for one or more documents which the user shares with the contacts or the collaborative group, saving an initial version of the shared document and then setting a correspondent sharing permission and a correspondent sharing time limit;
• and
• (c) after finishing setting the sharing permission and the sharing time limit, automatically sending notification messages to the correspondent contacts or the correspondent collaborative group for readily notifying by the message account;
• and
• regularly reminding the sharing users to notice the time limit according to the sharing time limit by the message accounts of all sharing users of the shared document.