This paper examines the electrical properties of V-doped SrZrO3 sputtered films showing bistable on/off resistive switching. The temperature dependence of dc sweep I-V data in the range of 25-100°C implies the prominent role played by the off-state conduction in determining the R-switch ratio. The defects in off-state are investigated via Frenkel-Poole relation and the associated trap energy extraction. It is found that the oxygen vacancies are the possible major defects in off-state and are verified by the treatment of N2 and O2 annealing ambience hereafter. The nearly unchanged currents suggest the relatively more stable nature in on-state, which is consistent with the following findings: 1) the frequently observed I-V jiggle during on to off switching, 2) successful forming only found for sweep direction to on-state, 3) the better thermal disturbance immunity by longer retention for on-state, 4) the shorter pulse width needed to on-state switching for electric pulse induced resistance (EPIR) effect.