In a method of controlling on-die termination (ODT) in a memory system including a plurality of memory units that shares a data bus to transfer data, ODT circuits of the plurality of memory units are enabled into an initial state, a resistance value of the ODT circuit is set to a first resistance value, of at least one write non-target memory unit among the plurality of memory units during a write operation on a write target memory unit among the plurality of memory units, and a resistance value of the ODT circuit is set to a second resistance value, of at least one read non-target memory unit among the plurality of memory units during a read operation on a read target memory unit among the plurality of memory units.