The dielectric constant, dielectric loss, and ac conductivity of polyblends of cellulose acetate hydrogen phthalate (CAP) and poly (vinyl pyrrolidone) (PVP) of different compositions were measured in the temperature range of 300-430 K and in the frequency range of 50 Hz-100 kHz. In the blends, the dielectric constant as well as the dielectric loss as a function of the temperature display a single peak corresponding to the glass transition temperature (T-g) in the region between the Tg values of the pure polymers. The T-g values observed agree well with those values obtained from DSC. Dielectric studies show that CAP forms a miscible blend with PVP. Ac conductivity values were calculated from the dielectric data and the conduction mechanism is discussed.