A mode adaptation method for performing mode switching between a single-user MIMO (SU-MIMO) mode and a multi-user MIMO (MU-MIMO) mode includes reporting, by a base station, a MIMO feedback mode to a mobile station, receiving a feedback information determined on the basis of the MIMO feedback mode from the mobile station; and determining a MIMO feedback mode based on the feedback information. The MIMO feedback mode indicates whether it is single-user MIMO or multi-user MIMO and includes a number of mobile stations (MSs) transferred at one time. As a result, the method maximizes a system throughput simultaneously while effectively reducing an amount of feedback information.