A memory system for transmitting data to and receiving data from a host apparatus includes a semiconductor memory and an access-controlling part. The semiconductor memory has storage areas identified by physical addresses, stores data in each of the storage areas, performs data write in accordance with a request made by the host apparatus. The access-controlling part selects a recommended address, which is recommended to be used in a next data write, on the basis of operation information about a factor that influences time consumed for data write in the semiconductor memory, and outputs the recommended address to the host apparatus.