A non volatile memory device and a memory system having the same are disclosed. The non volatile memory device may include a memory cell array having a plurality of non volatile memory cells, a DRAM interface for exchanging data, a command and an address with an external device, a controller for selecting one of the memory cells in response to the address and performing a control operation for one of outputting data of the selected memory cell to the external device in response to the command and storing data received from the external device, and a DRAM buffer memory. The DRAM buffer memory has dynamic memory cells, and each of the dynamic memory cells has one transistor with a floating body.