Nd10.2Fe89.8-xCx (x = 0.0, 2.6, 5.2, 7.8) powder were prepared by arc smelting and ball milling. The structure and morphology of the powder were investigated by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The electromagnetic parameters of the powders were measured by vector network analyzer (VNA) at room temperature. Microwave absorbing properties of Nd10.2Fe89.8-xCx (x = 0.0, 2.6, 5.2, 7.8) depend sensitively on the compositions. The minimum absorption peak frequency shifts to the higher region upon the C content. The minimum reflectivity value of Nd10.2Fe84.6C5.2 can achieve to -13.2 dB at 5.2 GHz and the bandwidth of R < -10 dB achieve 1.2 GHz with the best matching thickness of 1.8 mm. The minimum absorption peak shifts towards lower frequency region with absorbing coating thickness increasing.