6This paper reports results of measurements performed on carbon fiber-epoxy composite ( unidirectional sample ) at microwave frequencies in the X-band (8-12 GHz ). These measurements were performed on pure epoxy and 50 wt% composites using one and two specimens with different separating distances between them. The measurements included the insertion loss (IL), the return loss (RL) where the shielding effectiveness (SE) was deduced from both the IL and RL as a function of the frequency. The return loss, insertion loss and shielding effectiveness show relatively low frequency dependence. It was found that the SE value reaches around 12dB for one specimen, and 15 dB for two specimens in contact at 8 GHz. The SE increases to 28 dB when the spacing between the two specimens exceeds 50 mm,       at 8 GHz. The two specimen arrangements enhances the SE of this unidirectional composite material compared with one layer case. The results suggest that this carbon fiber-epoxy composite could be used in some micro-wave applications.