In this work, temperature dependent electrical and dielectric properties of the Au/Ti/HfO2/n-GaAs structures were investigated using capacitance-voltage (C-V) and conductance voltage (G-V) measurements in the temperature range of 60-320 K by steps of 20 K at 1 MHz. The dielectric constant (epsilon'), dielectric loss (89, dielectric loss tangent (tans) and ac electrical conductivities (sigma(ac)) have been calculated as a function of temperature. These values of the epsilon', epsilon '', tans delta and sigma(ac) have been found to be 2.272, 5.981, 2.631 and 3.32 x 10(-6) (Omega(-1)cm(-1)) at 80 K, respectively, 1.779, 2.315, 1.301 and 1.28 x 10(-6) (Omega(-1)cm(-1)), respectively at 320 K. These decrease of the dielectric parameters (epsilon', epsilon '', tans delta and sigma(ac)) have been observed at high temperatures. The experimental results show that electrical and dielectric properties are strongly temperature and bias voltage dependent. (C) 2017 Elsevier B.V. All rights reserved.