Abstract: A method of synchronizing character information by data classification in an on-line game system is disclosed, which includes the steps of: transferring character information including position data, which is generated from a positional shift of a first user's character, or motion data, which is generated from a motional change of the character, to a second user; receiving the character information by the second user; determining a data type of the character information; and processing the character information with reference to the data type.