This study develops an effective, simple, and low-cost method through metal–organic chemical vapor deposition for manufacturing carbonyl iron (CI)-coated hollow cenospheres(Ce) as new composites for microwave absorption. Structure and morphology analyses demonstrate that the composites have a complete core/shell structure with Ce as the core and CI layers as the shell. Compared with Ce, the composites have higher complex permeability and permittivity, indicating their improved absorption capacity. The measured electromagnetic parameters are used to analog and calculate the reflectance curves of Ce and Ce@CI coating under the condition of thickness d=2mm. The absorption peak of the Ce@CI sample shifts to the high frequency, and the minimum reflection peak decreases to ? 26.2dB. The frequencyat less than – 10dB bandwidth increases to 6 GHz, which covered the entire Ku band.