Abstract: By adding cobalt to CoSb, different Co1-xSbx (0.17≤x≤0.44) alloys have been synthesized to study the ac characteristics of the material. The ac measurements such as permeability and skin depth are calculated using high frequency and dc resistance of samples. It is observed that the permeability of the sample decreases with decreasing frequency of ac input signal and skin depth increases with decreasing frequency of ac input signal. The skin depth is observed to be sensitive to cell parameters. The results are discussed using microscopic as well as macroscopic models.