A data accessing method and system for a memory storage apparatus are provided. The method includes: performing a near field communication between a memory storage apparatus and an electronic apparatus, and receiving a first password from the electronic apparatus by the memory storage device in the near field communication. The method also includes: recording the first password in a memory unit of the memory storage apparatus. The method further includes: when the memory storage apparatus is not connected to the electronic apparatus or a host in a predetermined time after the memory storage apparatus receives the first password, deleting the first password recorded in the memory unit; and when the first password recorded in the memory unit is the same as a second password in the memory storage apparatus, allowing the electronic apparatus or the host to access the memory storage apparatus by the memory storage apparatus.