A method and system for automatically collecting information in messaging system. A method in accordance with an embodiment includes: setting a flag indicating an information collection and an initiation flag for a message for requesting information collection by an information requestor; generating a unique identifier for identifying a task for the information collection, and sending the message; when replying to the message for requesting information collection, setting a reply flag for a replied message and sending the replied message, wherein information required to be collected is included in the replied message; and extracting the information required to be collected by the task for the information collection identified by the unique identifier from the replied message in accordance with the flag indicating an information collection and the reply flag, consolidating the information into a single summary document, and providing the summary document to the information requester.