A selection diversity system using a decision feedback equalizer which has excellent tracking ability performance and equalization ability performance for frequency selective fading and a diversity effect against Rayleight fading. In a selection diversity system using a decision feedback equalizer, a decision data symbol of the equalizer output of a branch in which an average estimation error over a plurality of symbols is minimum is selected and combined, and the selected decision data symbol is used to recalculate the estimation error of every decision feedback equalizer and the tap gain coefficient of the decision feedback equalizer is updated using the recalculated estimation error, thereby overcoming the step out by the integration of the estimation error and the random selection error which is caused by the selective combined diversity system.