ABSTRACT:: Water (aqueous solution) in the very cramped space often shows some paradoxical features. Microtubules and their textural composite hydrate system, nuclear envelope inside the cell, the places of plasma membrane infolding and cell junction and cell adhesion outside the cell possess lots of nano-scale (10-10 nm) narrow spaces. Various body fluids (nano-slit water) including intracellular fluid, extracellular fluid and the others must be filled in these narrow slot spaces. The nano-slit water can also exist inside some globular protein molecules. Nano-slit water in the human tissues shows abnormal properties, such as acute rise of viscosity, sudden drop of ice point, etc.Hu YJ, Mao LJ, Chen XD, Zhang Y, Sun RH, Piao DX.A hypothesis of textural composite hydrate system (III): Nano-slit water in human body.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu. 2009;13(29):5767-5770. [http://www.crter.cn http://en.zglckf.com]