Memory Card and Accessing Method and Accessing System for the same

In a memory card and accessing method and accessing system for the memory card, the accessing method and accessing system are adapted to data access between a memory card and a machine using a first operation system. The accessing method firstly checks whether the data in the memory card is stored according to a data storage type supporting both the first operation system and a second operation system. When the data is not stored according to the data storage type, the machine is prohibited from accessing the memory card. A version value is stored in the memory card, wherein the version value is a value different from a predetermined version value. The second operation system deems the memory card un-accessible when the version value is confirmed to be not the predetermined version value.