Plasmonic　structures　possess　rich　physics　related　to　the　sensitivity　of　plasmon　resonance　to　the　change　in　the　environmental　dielectric　constant,　the　enhanced　light　scattering　and　optical　extinction,　and　the　local　field　enhancement　enabled　strong　light-matter　interactions,　which　have　been　applied　in　refractive-index　sensors,　optical　feedback　in　various　micro-　or　nano-cavity　lasers,　surface　enhanced　Raman　scattering　spectroscopy,　and　high-sensitivity　molecular　detection.　However,　ultrafast　optical　response　is　another　important　aspect　of　plasmons,　which　can　be　utilized　to　achieve　switching　of　optical　signals　in　different　spectral　bands.　These　optical　switching　designs　are　very　important　for　applications　in　optical　logic　circuits　and　optical　communication　system.　In　this　review,　we　summarize　a　series　of　reports　on　ultrafast　plasmonic　optical　switches,　where　we　focus　our　discussions　on　the　structural　and　device　designs,　instead　of　on　their　physics.　By　categorizing　the　designs　of　optical　switches　into　different　groups　by　their　featured　performances,　we　intend　to　propose　the　development　trend　and　the　commonly　interested　mechanisms　of　such　ultrafast　optical　switches.　We　hope　this　review　will　supply　helpful　concepts　and　technical　approaches　for　further　development　and　new　applications　of　ultrafast　optical　switching　devices.