A method for setting modes of data transmission, adapted to the base station device provided. The method includes steps of: receiving a signal quality indicator and a value of interference cancellation capability from a terminal device; obtaining a power difference according to the signal quality indicator by subtracting a reception power of the terminal device from a transmission power of the terminal device; comparing the power difference with the value of interference cancellation capability, and setting the terminal device as a first type terminal device only allowed to apply half duplex transmission or a second type terminal device allowed to apply full duplex transmission according to the comparison result.