Embodiments of the present invention provides a MIMO communication system based on random beamforming and its user scheduling method. The system includes: a transmitter that is used to transmit the data frame including at least the channel estimation signal and the user data; and at least one receiver that is used to receive the data frame from the transmitter and to produce the corresponding feedback information and recover the user data. The transmitter produces the scheduling information according to the feedback signal and utilizes the scheduling information to implement adaptive user scheduling. The scheduling information includes the scheduled users, data streams that should be supported by each scheduled user and the transmit beam adopted by each data stream. Embodiments of the present system can schedule the users with fixed number or adaptively according to the instant channel condition as well as different feedback information so that the intelligence of the system control and communication stability can be improved to approach the maximum system capacity.