Abstract
Our researching used molecular dynamics in nano-meter to research the different of physical property of poly(vinyl alcohol) solution with ionic，by calculating some basic properties，for example，radial distribution function，end to end distance，gyraiton radius，number of hydrogen bond and diffusion coefficient，to find the behavior of poly(vinyl alcohol) in solution。From resulting，when we added in different quantity ion，the poly(vinyl alcohol) have shrinking behavior， we can get the same result from the number of hydrogen bonds。