ZnO　nanowires　(NWs)　were　grown　on　Si(100)　substrates　at　975　°C　by　a　vapor-liquid-solid　method　with　~2　nm　and　~4　nm　gold　thin　films　as　catalysts,　followed　by　an　argon　plasma　treatment　for　the　as-grown　ZnO　NWs.　A　single　ZnO　NW-based　memory　cell　with　a　Ti/ZnO/Ti　structure　was　then　fabricated　to　investigate　the　effects　of　plasma　treatment　on　the　resistive　switching.　The　plasma　treatment　improves　the　homogeneity　and　reproducibility　of　the　resistive　switching　of　the　ZnO　NWs,　and　it　also　reduces　the　switching　(set　and　reset)　voltages　with　less　fluctuations,　which　would　be　associated　with　the　increased　density　of　oxygen　vacancies　to　facilitate　the　resistive　switching　as　well　as　to　average　out　the　stochastic　movement　of　individual　oxygen　vacancies.　Additionally,　a　single　ZnO　NW-based　memory　cell　with　self-rectification　could　also　be　obtained,　if　the　inhomogeneous　plasma　treatment　is　applied　to　the　two　Ti/ZnO　contacts.　The　plasma-induced　oxygen　vacancy　disabling　the　rectification　capability　at　one　of　the　Ti/ZnO　contacts　is　believed　to　be　responsible　for　the　self-rectification　in　the　memory　cell.　©　2016　by　the　authors;　licensee　MDPI,　Basel,　Switzerland.