Memory card including connector for other memory card independently interfacing host using mmc protocol

A memory device including a connector for interfacing the other memory device with independence of a host is provided to extend a memory, and enable the host to interface the memory device and the other memory device directly by connecting the other memory device to the connector and inserting the memory device connected with the other memory device into a slot of the host. An internal bus(222) receives commands or data from a host(210) through a plurality of I/O(Input/Output) pins(221) by using a MMC(Multimedia Memory Card) protocol. A connector(228) is electrically connected to the internal bus and is connected to a second memory device(230) directly interfaced with the host by using the MMC protocol. A first controller(224) outputs at least one control signal based on the command received from the host through the I/O pints. A first data storing part(226) writes the data received from the host through the I/O pins or deletes the stored data depending on the control signal.