Metasurface devices greatly enrich the interaction between light and matter， promoting the development of planar optics. In recent years， with the rapid development of terahertz （THz） technology， dynamically tunable terahertz devices have been widely studied. Liquid crystal （LC） is a unique soft matter that combines the fluidity of liquids and the order of crystals， making it indispensable in the field of displays and spatial light modulations. The integration of liquid crystals and metasurfaces enables tunable terahertz devices. In this review， we summarize three types of liquid-crystal based terahertz metasurfaces and their research progress， including liquid crystal planar terahertz devices， liquid crystal integrated metal metasurfaces， and liquid crystal integrated dielectric metasurfaces. Furthermore， techniques for fabricating liquid crystal microstructures as well as liquid-crystal integrated metal or dielectric metasurfaces are introduced. Due to the excellent responsiveness of liquid crystal metasurfaces to external stimuli including electric fields， magnetic fields， heat and light， the amplitude， frequency， phase， and polarization state of terahertz waves are dynamically manipulated. The tunable terahertz metasurface devices based on liquid crystals drastically promote the application of terahertz in imaging， communication， and sensing fields.

liquid crystal;metasurface devices;terahertz;tunable devices