The core component of the direct evaporative cooler is the filler,and its performance have a direct impact on the efficiency of the heat exchanger. At present,there are several fillers in common use,for example,inorganic filler(such as Munters’GLASdek),organic filler(such as Munters’CELdek) and aluminum foil filler.Although a large number of scholars have focused on the heat and mass transfer process on the surface of all above fillers,no one have done the comparative experiment of all these fillers in the same conditions.In these experiments,we take five fillers to study their performance in almost the same conditions,including GLASdek,CELdek,aluminum foil, the porous ceramic filler used in cooling towers, and the blue PVC fill offered by a domestic company.And there’re availabe some conclusions in order to provide guidance for engineering application.The results show that all fillers have their own advantages and disadvantages and we must choose it according to the specific situation.The efficiency of the porous ceramic is significant and can be used as the filler in direct evaporative coolers.