Abstract: Microwave absorbing properties of carbon fiber felt and parallel-arranged carbon fiber composites were investigated respectively. The results show that the absorbing properties of parallel-arranged composites were affected greatly by the distance and content of carbon fibers. In this research, the composites obtained a reflection loss above 10 dB over 3 GHz bandwidth. The carbon fiber felt materials exhibited promising characteristics of absorption over the frequency range of 8 GHz~18 GHz with 0.27 wt% felt. The properties were affected mainly by the content of felt.