Complex impedance spectroscopy has been employed to investigate the conduction behavior of (Ba,Sr)(Zr,Ti)O3 thin films in the low- and high-resistance states for resistive switching applications. The domination of the grain bulk effect on the resistive switching is demonstrated. The analyses of activation energies for the conduction in the low- and high-resistance states have been executed comparatively. It is proposed that the first and the second ionization of oxygen vacancies are responsible for the conduction in the low- and high-resistance states, respectively. The transition of conduction mechanism is also discussed.