A method for operating a multi-transaction memory system, the method includes: storing Logical Block Address (LBA) information changed in response to a request from a host and a transaction identification (ID) of the request into one page of a memory block; and performing a transaction commit in response to a transaction commit request including the transaction ID from the host, wherein the performing of the transaction commit includes: changing a valid block bitmap in a controller of the multi-transaction memory system based on the LBA information.