A memory system may include a memory including a cell array having a plurality of word lines and an address storage unit that stores an address in response to a capture command, wherein the memory sequentially refreshes the word lines in response to a refresh command at a set cycle, and refreshes a word line corresponding to the stored address in response to the refresh command when the address is stored in the address storage unit; and a memory controller transmitting the refresh command to the memory at the set cycle when a word line satisfying one or more of conditions that the number of activation times is equal to or more than a reference number and an activation frequency is equal to or more than a reference frequency is detected, and transmitting the capture command and an address of the detected word line to the memory.