Abstract: In order to overcome the disadvantage of urethane pyramids in manufacturing technology and application, a granular balk cargo with perlite, expanded polystyrene（EPS） and particles coated with carbon black as the base materials is studied. Then it is filled into a model with special configuration as a new microwave absorbing materials. The testing result of this absorber is close to the urethane pyramids which are commonly used in microwave chambers.