The present invention discloses an electronic device using a memory to expand storage capacity, and the device includes a main board and a data storage module. The main board includes at least one interface card slot, and the data storage module includes at least one storage interface card, and a plurality of memory slots disposed on the storage interface card for movably inserting a memory. The memory is for storing data, and the storage interface card is inserted into the interface card slot. With the memory slot on the storage interface card, the memory can be expanded conveniently, and the storage capacity can be increased dynamically as needed. The invention also enhances the security, performance, and vibration resisting function of the data storage.