A method for adaptively deciding number of feedback resource blocks in a downlink which comprises that a base station (500) determines a mode corresponding to the number of the feedback resource blocks which a user equipment feeds back by monitoring performance of a wireless cell and number of the user equipments (100) and transmits the mode to the user equipments (100) through signaling; the user equipments (100) listens to the mode and adaptively decides the number of feedback resource blocks by conditions of itself and feeds back downlink channel quality indicator information to the base station (500) according to Best channel quality indicator number or Threshold based feedback algorithm; and the base station (500) performs resource scheduling according to the feedback information. The present invention provides a method for adaptively deciding the number of feedback resource blocks based on base station signaling and user equipment decision, with respect to Best channel quality indicator number or Threshold based feedback algorithm in downlinks, thus insuring the performance of the wireless cell.