The present invention discloses a dynamic transmission power control method for a transmitter of a communication system which comprises the transmitter and a plurality of receivers. The transmitter is coupled to the plurality of receivers via a plurality of corresponding outgoing links. The transmission power control method comprising collecting a plurality of suggested transmission power back-off levels for the plurality of outgoing links to the plurality of receivers and/or and a plurality of channel characteristics corresponding to the plurality of outgoing links from the plurality of receivers; and determining an allowable transmission power back-off level for a desirable receiver among the plurality of receivers according to the plurality of suggested transmission power back-off levels and the plurality of channel characteristics.