Abstract: Using amphiphilic nanofibrillated cellulose (NFC) as a green dispersing agent to exfoliate and disperse layered clay in water. The NFC-dispersed monolayer clay nanoplatelet dispersion with excellent stability and high yield was obtained, and the morphologies of NFC and NFC-dispersed monolayer nanoclay suspension were characterized with AFM and TEM. Herein, NFC and NFC-dispersed monolayer clay nanoplatelets were combined to prepare highly transparent flexible film. As the content of monolayer clay nanoplatelets is 50wt%, the resultant NFC/monolayer clay nanoplatelet compound film exhibits about 90% transparency at 600-800 nm and a low transmission haze. NFC/monolayer clay film presents excellent ultraviolet screening properties, which can completely blcoks ultraviolet C (UVC, 100-290 nm) and most of ultraviolet B (UVB, 290-320 nm). The successful preparation of NFC-dispersed stable monolayer clay nanoplatelet dispersion will not only expand their application fields but also improve the performance of monolayer nanoclay matrix composites.